How to use Source Map Inspector
- Paste a bounded flat version-3 map with sources, names and mappings.
- Enter a one-based generated line and zero-based column.
- Review the preceding mapping segment and source exposure inventory, then export the report.
Example: Source Map Inspector
Look up positions in a flat version-3 source map and report source inventory without exporting embedded source text.
Options
- Position convention
- Generated and original lines are displayed from one; columns start at zero. Lookup stays on the requested generated line.
- Embedded source
- The report counts sourcesContent characters but omits the actual embedded code from downloads. Source paths themselves can be sensitive.
Supported inputs and limits
Where your input is processed
This tool processes your input in this browser. Your text and files are not uploaded to UseFreeTools. Check this tool's limits for anything it may save on your device.
A mapping does not cover every nearby character
Lookup uses the greatest preceding segment on the same generated line. A one-field segment marks an unmapped region rather than carrying a previous source mapping forward. The tool does not execute code, fetch sourceRoot addresses or establish whether a deployed server exposes the map.
Questions about Source Map Inspector
Can I inspect indexed sections?
This version accepts flat maps only and refuses indexed maps.
Is embedded code copied into the report?
Only its presence and character count are exported.
Why can lookup be unmapped?
The preceding segment can explicitly stop a mapping, or the line may have no applicable segment.