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HTTP User-Agent Builder
Build a User-Agent value from product/version tokens and an optional safe comment.
Product/version tokens, one per line, Optional comment
http-user-agent-builder.json (complete report and generated source where applicable)
Browser only
Runs locally in your browser. Your files, pasted content and generated output are not uploaded. Reset clears this tool’s working data.
This tool needs JavaScript. If it does not load, refresh the page and try again.
How to use this tool
- Enter values using the displayed examples; observe the documented input shape and limits.
- Choose Calculate result. Review the complete JSON report and any generated source text it contains.
- Download result to save the complete report; copy generated source into your project when relevant. Reset restores examples and clears output.
Examples
Product/version tokens, one per line: ExampleBot/1.0
Library/2.0
Optional comment: test client
Limitations
- Header source only; no browser emulation or identity verification. Comments are plain printable ASCII without parentheses/backslashes.
- Maximum 100,000 UTF-16 units per field, 400,000 UTF-8 combined input bytes, 4 MiB output and 30 seconds in a local worker. Tool-specific bounds may be tighter.
- Generated source is contained in the JSON download and is never executed. Local inspection does not verify remote systems or establish standards certification.
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