Introducing the ultimate guide to the "13 Amazing Overhead Scanners for 2023." If you're in need of a versatile and efficient scanner that can capture crisp images and documents, look no further. In this comprehensive article, we will delve into the top overhead scanners of 2023 that are revolutionizing the way we scan and digitize our documents. Whether you want to streamline your office workflow or simplify your personal scanning needs, these state-of-the-art scanners offer an array of impressive features and cutting-edge technology. Stay tuned to discover the perfect overhead scanner to meet your requirements in the coming year.
Overall Score: 7.5/10
The VIISAN S21 Large Format Scanner is a powerful tool for capturing A2 size documents with high resolution. It features intelligent scanning software that enhances the scanning process by digitally flattening curved pages, removing fingerprints, and repairing damaged edges. The scanner also has adjustable height and built-in 3-level LED light control for clear photos even in low-light conditions. With multi-language OCR and the ability to convert scanned files into PDF or editable Word/Excel/Epub/Txt files, it offers convenience and versatility. The S21 is compatible with both Windows and macOS systems and comes with a 1-year warranty. Overall, it is a reliable and efficient scanner for professional use.
Key Features
- A2 Large Format Scanner
- 27MP High Resolution
- Auto-Flatten & Fingerprint Removal Technologies
- Adjustable Height
- Multi-Language OCR
- Run On Windows & mac OS
Specifications
- Dimension: 14.17Lx8.27Wx18.70H
- Size: A2
Pros
- High-quality scanning with excellent resolution
- Intelligent scanning software with various features
- Adjustable height and built-in LED lights
- Compatible with Windows and mac OS
Cons
- Setup takes up more space compared to flatbed scanners
- No manual boundary setting for scan or cropping
- Auto-detect works poorly with dark images
- Some users experienced distortion on images
The VIISAN S21 Large Format Scanner is a reliable and efficient tool for capturing A2 size documents. With its high resolution and intelligent scanning software, it offers excellent scanning quality. The adjustable height and built-in LED lights provide convenience and flexibility. While there are some limitations in terms of space and manual settings, the overall performance of the scanner is commendable. It is especially useful for professionals who regularly scan large format journals, newspapers, and maps. The ability to convert scanned files into editable formats adds to its value. With a 1-year warranty and reliable customer support, the VIISAN S21 is a suitable choice for those in need of a versatile and feature-rich document scanner.
Overall Score: 8.5/10
The Fafeicy USB2.0 High Definition Scanner is a portable document camera designed for A4 format scanning. It comes with a high definition 8MP camera and 6 LED automatic light filling modules, allowing for quick and high-quality scanning of various document types. The scanner is foldable and made with high-quality ABS materials, making it convenient and durable. With a USB2.0 interface and 5V input voltage, it is compatible with systems like Windows XP, WIN 7, WIN 8, and WIN 10. The scanner is easy to install and operate with related software, making it a versatile and user-friendly device.
Key Features
- A4 format with 8MP high resolution camera
- 6 LED automatic light filling modules
- Supports JPG, GIF, BMP, TIF, PDF, PNG
- Foldable and portable design
- USB2.0 interface with 5V input voltage
Specifications
Pros
- High definition and high-speed scanning
- Foldable and portable design for convenience
- Durable construction with high-quality ABS materials
- Compatible with various Windows systems
Cons
The Fafeicy USB2.0 High Definition Scanner is a reliable and efficient device for users in need of portable document scanning. With its high definition camera and automatic light filling modules, it delivers excellent scanning quality and speed. The foldable and portable design adds to its convenience, while the durable construction ensures longevity. Compatibility with Windows systems makes it accessible for a wide range of users. Overall, the Fafeicy USB2.0 High Definition Scanner is a worthwhile investment for those seeking a compact and versatile scanning solution.
Overall Score: 7.5/10
The iCODIS Document Camera & Overhead Scanner X3 is a portable scanning device that offers high-definition capture size A3 and multi-language optical character recognition (OCR). It is designed for teachers conducting online teaching and students engaged in distance learning. With powerful basic functions and software, including an 8-megapixel camera, LED fill lights, and intelligent continuous shoot, it is perfect for various occasions such as making art books, live-streaming, and Zoom meetings. The scanner is easy to use, install, and transport, making it convenient for users. However, it is important to note that the software is not compatible with Mac OS and is only supported on Windows. The iCODIS scanner provides a useful tool for digitizing documents and exploring scanning capabilities without a large budget.
Key Features
- 8-megapixel camera with 3264×2448 resolution
- 4 LED fill lights
- A3 coverage
- Intelligent continuous shoot
- Ocr
- Automatic image correction and segmentation
Specifications
- Color: Grey
- Dimension: 9.40Lx3.10Wx13.80H
Pros
- Portable and easy to use
- Powerful basic functions and software
- Suitable for various occasions
- Useful for beginners with a limited budget
- Ability to export to searchable PDF and Word documents
Cons
- Not compatible with Mac OS
- Grainy and low-quality scans for images
- Insufficient lighting for color and glossy documents
- Limited compatibility with certain computers
The iCODIS Document Camera & Overhead Scanner X3 is a handy device that offers a range of functions for teachers and students. While it may have some limitations, such as compatibility issues and subpar image quality for certain types of documents, it provides great value for the price. This scanner is especially useful for individuals on a limited budget or those looking to explore document digitization. Overall, the iCODIS scanner is a reliable tool for online teaching, distance learning, and general document scanning needs.
Overall Score: 8/10
The KC5M01 High Definition Scanner is a versatile and portable document camera that offers high-quality scanning capabilities. With its 8MP high-resolution camera, it can quickly and efficiently scan various document formats, including JPG, GIF, BMP, TIF, PDF, and PNG. The scanner is compatible with P4 or other CPUs of the same level, with 512M memory or above, and works seamlessly with Windows XP, Windows 7, Windows 8, and Windows 10 when equipped with a USB 2.0 adapter card. Its foldable and portable design makes it convenient to install and operate the related software. The CMOS sensor and 6 LED automatic light filling modules ensure optimal image quality in various scenarios, making it suitable for professionals like teachers, lawyers, administrators, and more. Made with high-quality materials, this scanner is built to last and is easily transportable.
Key Features
- High definition 8MP camera for fast document scanning
- Supports various document formats
- Compatible with Windows XP, 7, 8, and 10
- Foldable and portable design for easy installation and operation
- Suitable for professionals in various fields
- Durable and long-lasting
Specifications
Pros
- High-resolution camera for clear scans
- Supports a wide range of document formats
- Compatible with multiple Windows operating systems
- Convenient and portable design
- Ideal for professionals in different industries
Cons
- No specifications provided for detailed information
The KC5M01 High Definition Scanner offers a reliable and convenient solution for individuals who require high-quality document scanning. With its high-resolution camera and compatibility with various document formats, it provides clear and accurate scans for professionals like teachers, lawyers, and administrators. The foldable and portable design makes it easy to set up and use, while its durability ensures a long service life. The absence of detailed specifications may be a downside for some users who prefer more technical information. Overall, this scanner is a practical and efficient option for anyone in need of a versatile and portable document scanning device.
Overall Score: 8/10
The Document Scanner is a high-tech device that combines a 10MP HD camera and OCR technology to scan documents efficiently. With its one-button auto correction feature, it can intelligently correct skewed pictures and form them automatically within one second. The scanner supports batch automatic scanning of PDF, WORD, EXCEL, and TXT documents, making it ideal for professionals who deal with large amounts of paperwork. The powerful OCR function allows the scanner to convert document images to editable text with a recognition rate of over 98%. It also supports multi-language recognition, making it suitable for international users. The foldable and portable design, along with the ability to catch real-time video and display it, offers convenience for distance learning and online teaching. Overall, the Document Scanner is a versatile tool that provides efficiency and convenience for various professional and educational purposes.
Key Features
- High Efficiency
- OCR Function
- 10 MP Sensor
- Real Time Display
- Foldable and Portable
Specifications
Pros
- High Efficiency One-Button Auto Correction
- Powerful OCR Function with High Recognition Rate
- 10 MP Camera for Clear Real-Time Images
- Foldable and Portable Design
- Real-Time Video Display and Recording
Cons
- Only Compatible with Windows
The Document Scanner offers a seamless scanning experience with its intelligence and accuracy. Its high efficiency, combined with the OCR function, simplifies the task of digitizing documents and converting them into editable files. The 10MP camera ensures clear and precise images, even in low-light conditions. The foldable and portable design adds to its versatility, making it suitable for various professional and educational settings. The ability to catch real-time video and display it opens up new possibilities for distance learning and online teaching. However, the scanner is limited to Windows compatibility, which may be a drawback for some users. Overall, the Document Scanner is a reliable and user-friendly device that meets the scanning needs of professionals and educators.
Overall Score: 8.2/10
The Fujitsu ScanSnap SV600 Overhead Scanner is a high-quality scanner that offers great versatility and performance. With a maximum optical resolution of 1200 dpi, it delivers excellent image quality for both text and illustrations. Its innovative overhead design allows for scanning of a wide variety of objects, including books, posters, and even three-dimensional objects. The scanner is equipped with the PA03641-B301 model, ensuring reliable and efficient scanning capabilities. The software provided with the scanner offers features such as automatic correction of page curvature and removal of imperfections. While the scanner is not suitable for scanning photo albums, it excels in scanning books and documents, providing accurate and clear results. The scanner is easy to use and its compact design ensures convenience and portability. Overall, the Fujitsu ScanSnap SV600 Overhead Scanner is a reliable and versatile option for all your scanning needs.
Key Features
- PA03641-B301
Specifications
- Dimension: 0.00Lx0.00Wx0.00H
Pros
- High-quality scanning with a maximum optical resolution of 1200 dpi
- Versatile overhead design allows scanning of a wide variety of objects
- Software provides automatic correction of page curvature and imperfections
- Compact and portable design for convenience
Cons
- Not suitable for scanning photo albums
- Software can be clunky and confusing for some users
The Fujitsu ScanSnap SV600 Overhead Scanner is a reliable and versatile option for all your scanning needs. With its high-quality scanning capabilities and innovative overhead design, it offers excellent performance for a wide range of objects. The scanner’s software provides useful features, such as automatic correction of page curvature, ensuring accurate and clear results. While it may not be the best choice for scanning photo albums, it excels in scanning books and documents. Its compact and portable design adds to its convenience. Overall, the Fujitsu ScanSnap SV600 Overhead Scanner is a great investment for anyone in need of a versatile and efficient scanner.
Overall Score: 8/10
The Overhead Document Scanner is a versatile tool that offers high definition capture and real-time display. With its 10MP CMOS sensor and LED light, it can capture clear and detailed images even in dark or bright environments. It also supports projection and video recording, making it ideal for distance learning and online teaching. The Liftable book document scanner is easy to use, with a portable design and simple USB connectivity. It comes with the necessary software and is suitable for various purposes, including home, office, and educational use. Additionally, the scanner features auto correction technology for quick and efficient image correction. It supports batch scanning and is compatible with A3 and A4 documents in various formats.
Key Features
- HD Camera And LED Light
- Projection And Video Recording
- Easy To Use
- Auto Correction
- Widely Applicable
Specifications
- N/A
Pros
- High-resolution images with clear details
- Supports real-time projection and video recording
- Portable design for easy use
- Auto correction technology improves efficiency
- Compatible with various document formats
Cons
- Limited to Windows operating system
- Lacks detailed specifications
The Overhead Document Scanner is a reliable option for capturing and displaying documents with ease. Its high-resolution camera and LED light ensure clear and detailed images, while the projection and video recording capabilities enhance communication and sharing. The scanner’s portability and simple USB connectivity make it convenient for various users, whether at home, office, or in an educational setting. The auto correction feature saves time and effort by automatically adjusting skewed images. While it is unfortunate that the scanner is only compatible with Windows, it remains a versatile tool for document scanning and digitization. Overall, the Overhead Document Scanner offers great value and efficiency for its users.
Overall Score: 8/10
The Overhead Scanners, KC5M01 High Definition Scanner Portable Foldable 8MP Document Camera is a high-speed camera made of high-quality materials for durability and stability. It features an 8MP high-resolution camera that enables quick document scanning. With a CMOS sensor and 6 LED automatic light filling modules, it provides clear images. The scanner is compact, lightweight, and foldable, making it convenient for travel. Users can easily install and operate related software. Overall, the KC5M01 High Definition Scanner Portable Foldable 8MP Document Camera is a reliable and portable device for efficient document scanning.
Key Features
- Made of high-quality materials
- 8MP high-resolution camera
- CMOS sensor with 6 LED automatic light filling
- Compact and lightweight
- Foldable and portable
Specifications
- Dimension: 0.00Lx0.00Wx0.00H
Pros
- Durable and stable construction
- High-resolution camera for quick scanning
- Clear images with automatic light filling
- Compact and portable for convenience
- Easy installation and operation
Cons
The Overhead Scanners KC5M01 High Definition Scanner Portable is a practical and reliable tool for anyone in need of efficient document scanning. Its high-resolution camera and compact design make it easy to capture clear images while on the go. The durable construction ensures long-term usability, and the foldable feature adds convenience to storage and transportation. Whether you’re a student, professional, or hobbyist, this scanner offers a user-friendly experience. The ability to install and operate related software effortlessly enhances its functionality. With its excellent performance and portability, the KC5M01 High Definition Scanner Portable is a recommended choice for those seeking a versatile document scanning solution.
Overall Score: 8/10
Enabling GIS to the Social Scientist! A great many of the studies made in the humanities and social sciences have a geographical component. Modern Geographical Information Systems have come a long way, making it easier and more affordable for social scientists to utilize GIS technology. This book, written by Dr. Okabe at the University of Tokyo, presents the result of a six-year study on GIS-based studies in the humanities and social sciences. It covers various topics, such as the development of communities, tax income, crime rates, migration patterns, and more. The book also provides valuable insight into finding or establishing web resources for social scientists interested in GIS software.
Key Features
Specifications
Pros
Cons
GIS-based Studies in the Humanities and Social Sciences is a valuable resource for social scientists interested in utilizing GIS technology for their research. Dr. Okabe’s six-year study provides insights into the development of communities, tax income, crime rates, migration patterns, and more through the use of geographical information systems. The book also offers guidance on finding relevant software resources. With the advancements in GIS technology and the availability of cost-effective solutions, this book highlights the opportunities for researchers to analyze and visualize geographically oriented data. Whether you’re a beginner or an expert, this book offers valuable knowledge for integrating GIS into the field of humanities and social sciences.
Overall Score: 8.5/10
The 13 MP USB Document Camera is a versatile and powerful tool designed for teachers, remote workers, and distance learners. With its 13 megapixels image quality and 4K Ultra HD resolution, it captures stunning live images and videos. It can be used as a front-facing webcam for attending online lectures or as a document camera for demonstrating solutions and showcasing 3D objects. The portable design allows for capturing images and videos from all angles, making it ideal for various applications. It also features a 6-mode supplemental LED light, eliminating exposure problems in different lighting conditions. With plug and play functionality, it is compatible with popular video conferencing and recording tools. The 13 MP USB Document Camera offers high-quality performance and versatility for educational and professional use.
Key Features
- 13 Megapixels Image Quality
- Document Camera & Webcam Designed for Education
- Portable
- 6-Mode Supplemental LED light
- Plug and Play
Specifications
- Color: Off-white
- Dimension: 15.63Lx7.32Wx4.13H
- Size: Large
Pros
- High image quality at 13 megapixels
- Versatile use as a webcam or document camera
- Portable design for capturing images from all angles
- Supplemental LED light for difficult lighting conditions
- Easy plug and play functionality
Cons
- Unstable stand
- Limited software instructions
- Control visibility issues in certain positions
The 13 MP USB Document Camera is a powerful and versatile tool for educators, remote workers, and distance learners. With its high image quality, portable design, and versatile functionality, it offers a range of benefits for various applications. While the stand may be unstable and the software instructions limited, the overall performance and features of the document camera make it a valuable addition to any educational or professional setting. Whether used as a webcam or document camera, it provides exceptional image quality and ease of use. Despite some minor drawbacks, the 13 MP USB Document Camera is a recommended choice for those in need of a reliable and versatile imaging solution.
Overall Score: 9/10
The ScanAvenger Wireless Portable 1D&2D with Stand Bluetooth Barcode Scanner is a sleek handheld scanner that offers wireless connectivity and vibration capabilities. It does not require any software installation and can be used with Mac or Windows computers, Android or Apple mobile devices, and POS systems. This scanner is compatible with a wide range of barcodes, including 1D and 2D codes. It has a long transmission range of up to 493 feet and a rechargeable Li-Ion battery. The scanner comes with a smart charging stand that wirelessly transmits data and charges the scanner. Overall, this scanner is easy to use, fast, and accurate, making it a great tool for inventory management.
Key Features
- No software needed
- Bluetooth and USB scanner
- Vibration capabilities
- Next-gen smart charging stand
- Manual and auto sense scan modes
- Compatible with various types of barcodes
- Long transmission range
- Rechargeable Li-Ion battery
Specifications
Pros
- No software installation required
- Versatile connectivity options
- Fast and accurate scanning
- Long transmission range
- Convenient rechargeable battery
Cons
- Light on the stand can be blinding
- May experience double scans
- Limited compatibility with certain platforms
- No off button
- Switching settings via QR codes might be inconvenient
The ScanAvenger Wireless Portable 1D&2D with Stand Bluetooth Barcode Scanner is a reliable and efficient scanner for inventory management. It offers multiple connectivity options, fast scanning, and a long transmission range. The rechargeable battery and smart charging stand add to the convenience of this scanner. However, some users may find the light on the stand too bright and experience occasional double scans. Additionally, the lack of an off button and the need to switch settings via QR codes may be minor inconveniences for some. Overall, this scanner is a great tool for businesses and individuals in need of accurate and efficient barcode scanning.
Overall Score: 8.2/10
The Kedida Barcode Scanner is a handheld inventory 1D bar code scanner that is perfect for various settings such as supermarkets, warehouses, libraries, and more. It features plug and play functionality, allowing for easy setup without the need for drivers. With fast and precise scanning speeds of up to 300/sec, this barcode scanner ensures reliable and efficient performance even in challenging conditions. It is widely compatible with Windows, Mac OS, and Linux, and supports a variety of barcodes types. The durable and ergonomic design, along with the 6ft/2m long USB cable, provides flexibility and convenience during scanning. Kedida also offers excellent customer support with a 24-month warranty and lifelong technical assistance. Overall, the Kedida Barcode Scanner is a reliable and user-friendly tool for barcode scanning.
Key Features
- Plug and play, easy to use
- Fast and precise scan up to 300/sec
- Widely compatible with Windows, Mac OS, and Linux
- Supports a wide range of barcode types
- Durable and ergonomic design
- 6ft/2m long USB cable for flexibility
- 24-month warranty and lifelong technical support
Specifications
- Color: USB Barcode Scanner
- Dimension: 7.09L x 3.54W x 2.36H
Pros
- Easy to setup and use
- Fast and accurate scanning
- Compatible with various operating systems
- Supports multiple barcode types
- Durable and ergonomic design
- Long USB cable for flexibility
- Excellent customer support and warranty
Cons
- Some users experienced glitches
- Not compatible with Follett book management system
The Kedida Barcode Scanner is a reliable and efficient tool for barcode scanning needs. With its plug and play functionality, fast scanning speed, and wide compatibility, it offers convenience and accuracy in various settings. The durable and ergonomic design ensures long-lasting performance, while the 6ft/2m long USB cable provides flexibility during scanning. The scanner’s ability to read damaged and low-quality barcodes is a bonus. Customer support from Kedida is commendable, with a 24-month warranty and lifelong technical assistance. Although some users may encounter glitches and it may not be compatible with specific systems, overall, the Kedida Barcode Scanner is a great investment for those in need of a reliable barcode scanning solution.
Overall Score: 8.2/10
The Handheld USB QR Barcode Scanner Reader is a versatile and efficient device that offers superior recognition ability, three scanning modes, easy plug and play functionality, and professional anti-shock silicone design. It is compatible with various operating systems and software. With its fast and accurate reading speed, it can decode both 1D and 2D barcodes, including deformed or damaged barcodes. The handheld design and durable construction make it suitable for use in mobile payment, store, supermarket, and warehouse environments. This barcode scanner is a reliable and user-friendly tool for all your scanning needs.
Key Features
- Superior recognition ability with fast accurate reading speed
- Three scanning modes: key trigger, auto-induction, continuous
- Plug and play functionality with no drivers or batteries required
- Professional anti-shock silicone design for durability
- Code compatibility with various barcode formats
Specifications
- Color: Black
- Dimension: 5.12Lx2.76Wx2.76H
Pros
- Fast and accurate barcode scanning
- Easy to use with plug and play functionality
- Durable and protected against shocks and moisture
- Compatible with various barcode formats
Cons
- Software installation required for some systems
- Lack of included software for certain operations
The Handheld USB QR Barcode Scanner Reader is a reliable and efficient solution for all your scanning needs. With its superior recognition ability, three scanning modes, and easy plug and play functionality, it offers convenience and accuracy. The professional anti-shock silicone design ensures durability, while the code compatibility allows for versatility in scanning various barcode formats. Though software installation may be required for certain systems and operations, this barcode scanner offers excellent performance overall. Whether you need to scan barcodes in a store, supermarket, warehouse, or for mobile payment, this handheld scanner is a reliable and user-friendly choice.
Buyer's Guide: Overhead Scanner
Get ready to take your scanning experience to new heights with an overhead scanner! Whether you're a student, professional, or an avid collector, an overhead scanner can be a practical and efficient tool for all your document and image scanning needs. To help you make the right choice, we've put together this comprehensive buyer's guide that will navigate you through the world of overhead scanners. So, let's dive right in and discover all the key factors to consider.
Benefits of an Overhead Scanner:
- Space-saving: Overhead scanners typically have a compact design, making them perfect for small workspaces or on-the-go use.
- Quick and efficient: With their fast scanning capabilities, overhead scanners can save you precious time by capturing multiple pages in seconds.
- Versatility: These scanners are not limited to just documents. Many models allow you to scan various materials such as photos, books, and even 3D objects.
- Excellent image quality: Overhead scanners often feature high-resolution sensors, ensuring clear and detailed scans.
- Intuitive software: Many overhead scanners come with user-friendly software that simplifies the scanning process, offering options for cropping, rotating, and enhancing scanned files.
Key Factors to Consider:
- Scanner Size: Assess the available space in your working area and ensure that the dimensions of the overhead scanner you choose are suitable for your needs.
- Scan Resolution: Look for a scanner with a higher optical resolution for sharper and more accurate scans. A resolution of 600 dpi (dots per inch) or higher is recommended for detailed document or photo scanning.
- Scan Speed: Consider the speed at which the scanner can process documents. Faster scanning speeds can be beneficial if you have large quantities of documents to scan frequently.
- Connectivity Options: Determine how you plan to connect the scanner to your computer or other devices. Overhead scanners often provide USB, Wi-Fi, or Bluetooth connectivity options.
- Compatibility: Ensure that the scanner is compatible with your operating system (Windows, macOS, Linux, etc.) or any additional software you plan to use.
- Additional Features: Assess any extra features that may enhance your scanning experience, such as a built-in LCD screen, automatic document feeder (ADF), or multi-page scanning functionality.
- Price: Set a budget that aligns with your requirements, and compare prices across different brands and models to find the best value for your money.
- Warranty and Customer Support: Check for warranty details and the availability of reliable customer support should you encounter any issues with your scanner.
Frequently Asked Questions about 13 Amazing Overhead Scanner for 2023
Absolutely! Overhead scanners are ideal for scanning delicate documents, as they eliminate the need for direct contact with the scanner bed, reducing the risk of damage.
Yes, many overhead scanners have a large scanning area, allowing you to scan books or magazines without the need for disassembly. Consider checking the maximum document size supported by the scanner before purchasing.
Many overhead scanners are designed to be portable, especially those with compact and foldable designs. They are lightweight and easily transportable, making them suitable for use outside of your regular workspace.
While flatbed scanners require you to place your documents face-down on a glass surface, overhead scanners capture images from above. Overhead scanners are more suitable for scanning large quantities of documents quickly, whereas flatbed scanners are often preferred for scanning delicate or uneven materials.
Yes, some overhead scanners have the capability to scan 3D objects. These scanners use specialized software and built-in lighting to capture detailed 3D representations of objects. Confirm if the scanner you are interested in offers this feature.
Certainly! Most overhead scanners can accommodate documents of various sizes, including letter-sized, legal-sized, and smaller formats. Some even offer adjustable scanning areas to fit larger documents.
To keep your scanner in optimal condition, gently wipe the scanning bed with a soft, lint-free cloth and use a cleaning solution specifically designed for scanner glass if necessary. Avoid using harsh chemicals or abrasive materials.
Yes, many overhead scanners come equipped with automatic document feeder (ADF) functionality. This feature allows you to load multiple pages into the tray, and the scanner will automatically cycle through each page, capturing them one by one.
