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Choose a browser-based TN3270 terminal for your team

3270Web is a self-hosted IBM 3270 terminal accessed through a browser. It suits developers, testers and operators who want terminal access without deploying a desktop emulator to every client, plus recording, APIs and optional AI assistance. A server still has to run 3270Web and reach your TN3270 host; the browser alone does not connect directly to the mainframe.

Check the deployment fit

Question What to evaluate
Where does it run? A server or workstation using a supported native binary, Docker or Compose
Who can reach the host? The 3270Web service needs network access to the TN3270 endpoint
How do users sign in? Configure accounts and the host profiles each audience can use
What does the host require? Confirm TLS, terminal model, code page, LU routing and keyboard behaviour
Do you need automation? Record JSON flows, use the REST API or connect an MCP client
Do you need AI? Optional; choose your own provider or local model and its data policy

Use Installation, Shared Instances and Terminal Models to check requirements. Test your actual application before selecting a client; a compatible protocol does not guarantee identical behaviour for every screen or workflow.

Try it without a mainframe

  1. Follow Install and Run for your chosen method.
  2. Open the address shown by the installation instructions.
  3. On the connect page, choose Start sample app, or use sampleapp:petstore as the hostname.
  4. Navigate a short flow, enter fields and check the keyboard/PF keys you use.
  5. Record it, download the JSON, then replay it in debug mode and verify that it lands on the same result.

The bundled samples make the first evaluation independent of host access and production data. To measure concurrency later, pass a reviewed workflow to 3270Connect.

Understand costs and licensing

The current open-source release uses AGPL-3.0-or-later; commercial terms are also available. Read the licence guide for version history and deployment considerations. The open-source software has no acquisition fee; your hosting, operations and optional AI provider are separate costs. AI is not required for ordinary terminal use or recording.

3270Web runs s3270, part of the x3270 family, as a separate process. It adds a browser interface and associated workflows rather than replacing that protocol implementation. See Acknowledgements.

Choose the next step