# Source map position resolver — no upload

> Resolve a minified line/column back to the original source using a source map, in your browser. Nothing is uploaded — files stay in the tab.

Use a source map to resolve a line and column in minified code back to the original file, function, and position. Resolution runs on your device, with nothing uploaded.

A minified stack trace is useless without a source map. This resolver turns a bundle position into the original file, line, and function name, so you can actually locate the bug behind a production error.

Keeping it local means you don't upload your source maps — which can effectively reveal your source — to a third-party service.

## How to

1. **Add the source map.** Provide the .map file for your bundle.
2. **Enter a position.** Type the minified line and column from a stack trace.
3. **Resolve.** See the original file, line, and symbol.

## FAQ

### How does this help with production errors?

Production stack traces point into minified code. A source map translates those positions back to your original source, so an error at bundle.js:1:20481 becomes a real file and line.

### Do I need the original source?

The .map file is what's required; if it includes sourcesContent, you also get the surrounding code. Either way you get the original file and position.

### Is my source map uploaded?

No. Resolution runs in the browser, so your map and source stay local.


## Related tools

- [Format & minify](https://www.safepaper.app/dev/code-formatter)
- [Text diff](https://www.safepaper.app/dev/text-diff)
- [JSON toolkit](https://www.safepaper.app/dev/json-toolkit)
- [Gzip / Brotli](https://www.safepaper.app/dev/gzip)

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Canonical HTML: https://www.safepaper.app/dev/sourcemap-resolver
Markdown: https://www.safepaper.app/dev/sourcemap-resolver.md

There is no upload endpoint — your files are processed in this browser tab. Open your network tab and check.