VintaSoft Web TWAIN service (Windows edition) is the Windows service that provides Web API for accessing local TWAIN scanners for all users of local computer.

VintaSoft Web TWAIN service (Windows edition) is a .NET Framework 4.0 application and it can be used on any Windows (Windows 11/10/8.1/8/7/Vista; Windows Server 2025/2022/2019/2016/2012/2008) computer with installed .NET Framework 4+.

VintaSoft Web TWAIN service (Windows edition) provides access to 64- and 32-bit TWAIN scanners if the service is installed on 64-bit computer.
VintaSoft Web TWAIN service (Windows edition) provides access to 32-bit TWAIN scanners if the service is installed on 32-bit computer.

VintaSoft Web TWAIN service (Windows edition) can be accessed via HTTPS protocol using URL "https://localhost:25329/api/VintasoftTwainApi" or via HTTP protocol using URL "http://localhost:25319/api/VintasoftTwainApi".
Network ports 25319 and 25329 can be changed during or after installation of VintaSoft Web TWAIN service.

1. Installation of Vintasoft Web TWAIN service (Windows edition) to a local Windows computer

For installing VintaSoft Web Twain service (Windows edition) to your Windows computer you need to do the following steps:

• Download the ZIP-archive with Windows installer from URL: https://www.vintasoft.com/zip/VintasoftWebTwainService-15.1.0.zip
• Extract the setup EXE from ZIP-archive into a folder.
• Read "description.txt" file for information about command line parameters of installer.
• Run "VintasoftWebTwainService-15.1.0-setup.exe" file for installing VintaSoft Web Twain service onto your PC and follow the installation instructions.

2. Uninstallation of Vintasoft Web TWAIN service (Windows edition) from a local Windows computer

For uninstalling VintaSoft Web Twain service (Windows edition) from your Windows computer you need to do the following steps:

• Run uninstaller "<Vintasoft_Web_Twain_service_install_path>/uninstall.exe" and follow the deinstallation instructions.

3. Initialization of Vintasoft Web TWAIN service (Windows edition)

Vintasoft Web TWAIN service (Windows edition) has initialization file - "VintasoftWebTwainService.ini" file, which is located in the service folder.
"VintasoftWebTwainService.ini" file can contain the following settings:

• HTTPSERVICEPORT - defines the network port for web server that serves HTTP requests to the service. Default value is 25319.
• HTTPSSERVICEPORT - defines the network port for web server that serves HTTPS requests to the service. Default value is 25329.
• RUN32BITWEBSERVICE - defines a value indicating whether 32-bit service must be used. Parameter can have the following values: 0 - 64-bit service must be started; 1 - 32-bit service must be started. Default value is 0.
• TWAINLOGGING - defines the logging mode for the service. This parameter can have the following values: 0 - logging is disabled; 1 - logging is enabled; 2 - extended logging is enabled. Default value is 0.
  If logging is enabled, the service saves log-information to a log-file "C:\Users\%USERNAME%\AppData\Local\Temp\VSWebTwainService32-debug.log" or "C:\Users\%USERNAME%\AppData\Local\Temp\VSWebTwainService64-debug.log".

4. Getting information about status of Vintasoft Web TWAIN service (Windows edition)

Vintasoft Web TWAIN service (Windows edition) consists from Windows service (VintaSoftWebTwainService.exe file), which manages the web TWAIN service, and from web TWAIN service (VintaSoftWebTwainService32.exe or VintaSoftWebTwainService64.exe file), which serves requests to local TWAIN devices.

Information about status of Windows service (VintaSoftWebTwainService.exe file) is saved into log-file "<ServiceInstallPath>\VintaSoft\Web TWAIN Service 15.1\log\VSWebTwainService.log".

Information about status of 32-bit web TWAIN service (VintaSoftWebTwainService32.exe file) is saved into log-file "C:\Users\%USERNAME%\AppData\Local\Temp\VSWebTwainService32.log".
Debug information about work with 32-bit TWAIN devices is saved into log-file "C:\Users\%USERNAME%\AppData\Local\Temp\VSWebTwainService32-debug.log" if TWAIN logging is enabled.

Information about status of 64-bit web TWAIN service (VintaSoftWebTwainService64.exe file) is saved into log-file "C:\Users\%USERNAME%\AppData\Local\Temp\VSWebTwainService64.log".
Debug information about work with 64-bit TWAIN devices is saved into log-file "C:\Users\%USERNAME%\AppData\Local\Temp\VSWebTwainService64-debug.log" if TWAIN logging is enabled.

5. Troubleshooting

5.1 VintaSoft Web TWAIN service (Windows edition) is not available

If you have installed VintaSoft Web TWAIN service (Windows edition) to your Windows computer, but still see the error message that service is not available, please do the following steps:

• Open URL "http://localhost:25319/api/VintasoftTwainApi/Status" and see information about online status of web server that serves HTTP requests. If URL is not available, please check that system firewall allows access to port 25319 for VintaSoft Web TWAIN service (file "C:\Program Files (x86)\VintaSoft\Web TWAIN Service 15.1\VintasoftTwainService.exe").
• Open URL "https://localhost:25329/api/VintasoftTwainApi/Status" and see information about online status of web server that serves HTTPS requests. If URL is not available, please check that system firewall allows access to port 25329 for VintaSoft Web TWAIN service (file "C:\Program Files (x86)\VintaSoft\Web TWAIN Service 15.1\VintasoftTwainService.exe").

5.1.1. VintaSoft Web TWAIN service (Windows edition) is not working in Windows 7 and Chrome 84+

VintaSoft Web TWAIN service (Windows edition) uses Transport Security Layer (TLS), which is provided by .NET Framework. .NET Framework uses TLS, which is available in system (Windows 7).
Windows 7 supports only TLS 1.0 and 1.1 and this means that VintaSoft Web TWAIN service can use only TLS 1.0 and 1.1 in Windows 7.
Google removed support for TLS 1.0 and TLS 1.1 in Chrome 84 as written here. Starting from Chrome 84 only TLS 1.2 and higher is supported.
Unfortunately Chrome 84+ can be installed in Windows 7 and this means that Chrome 84+ can use only TLS 1.2+ in Windows 7.
VintaSoft TWAIN JavaScript API need to send CORS requests from web application domain (for example, your-domain.com) to VintaSoft Web TWAIN service (localhost). All modern browsers allow CORS request to "localhost" only for HTTPS connection.
VintaSoft Web TWAIN service is not working in Windows 7 and Chrome 84+ because VintaSoft TWAIN JavaScript API cannot create secure connection from Chrome 84+ (supports TLS 1.2+) to VintaSoft Web TWAIN service (supports TLS 1.0 and TLS 1.1).
If you still need to use Windows 7, please use Opera browser instead of Chrome. But the best solution is to update your Windows.

5.1.2. VintaSoft Web TWAIN service (Windows edition) is not working in Windows 7 and Firefox 74+

VintaSoft Web TWAIN service (Windows edition) uses Transport Security Layer (TLS), which is provided by .NET Framework. .NET Framework uses TLS, which is available in system (Windows 7).
Windows 7 supports only TLS 1.0 and 1.1 and this means that VintaSoft Web TWAIN service can use only TLS 1.0 and 1.1 in Windows 7.
Mozilla removed support for TLS 1.0 and TLS 1.1 in Firefox 74 and starting from Firefox 74 only TLS 1.2 and higher is supported.
Unfortunately Firefox 74+ can be installed in Windows 7 and this means that Firefox 74+ can use only TLS 1.2+ in Windows 7.
VintaSoft TWAIN JavaScript API need to send CORS requests from web application domain (for example, your-domain.com) to VintaSoft Web TWAIN service (localhost). All modern browsers allow CORS request to "localhost" only for HTTPS connection.
VintaSoft Web TWAIN service is not working in Windows 7 and Firefox 74+ because VintaSoft TWAIN JavaScript API cannot create secure connection from Firefox 74+ (supports TLS 1.2+) to VintaSoft Web TWAIN service (supports TLS 1.0 and TLS 1.1).
If you still need to use Windows 7, please search in internet how to enable TLS 1.0 and TLS 1.1 in Firefox 74+. Also you can use Opera browser instead of Firefox. But the best solution is to update your Windows.

5.2. TWAIN scanner works not correctly

If VintaSoft Web TWAIN service (Windows edition) is working, but you have a problem with TWAIN scanner, we recommend you to try the following things:

1. Get the latest version of TWAIN driver for your TWAIN scanner from web site of TWAIN scanner manufacturer and re-install the TWAIN driver.
   
   
2. Make sure you have the latest version of VintaSoft Web Twain service (Windows edition).
   
   
3. Some "bad" TWAIN drivers may fail if application tries to set "not supported" capabilities of TWAIN driver.
   Try to test scanner work using our TWAIN Simple Demo because TWAIN Simple Demo is very simple application, it just scans images from TWAIN scanner and does not set any capability of TWAIN device. All other our demos (TWAIN Advanced Demo, etc) set device capabilities.
   
   
4. If you still have the problem, please send information about your problem to our support team and we will try to help you.
   We need:
   • Snippet of your code. Working project which demonstrates the problem will be welcome.
   • Log-file generated by the TWAIN Data Source Manager.
   • Log-file generated by VintaSoft Web Twain service. Please read how to enable logging for VintaSoft Web Twain service (Windows edition) in "Initialization of Vintasoft Web TWAIN service" section above.

Here are steps you should do if you want to get the log-files generated by the TWAIN Data Source Manager:

1. Enable logging for the TWAIN Data Source Manager (add the system variable "TWAINDSM_LOG" with value "d:\twain.log")
   • Right click on "My Computer" icon
   • Select the "Properties" menu from the context menu
   • Select the "Additional" tab
   • Click the "Environment variables" button
   • Add system variable