Log Sanitizer FAQ
Common questions about privacy, supported formats, custom rules, and reversible masking.
- Does my log data ever leave my browser?
- No. Detection, masking and the mapping table all run in your browser, so the text you paste or the file you open is not sent to DevCraftKit. The page does not upload your log. Custom rules you create are saved only in your own browser's local storage.
- What log formats are supported?
- Log Sanitizer is regex- and field-aware, so it works on any plain-text log: Windows Event JSON, Syslog, CEF, LEEF, Apache/Nginx access logs, JSON logs, key=value logs, and raw application stack traces. There's no strict schema requirement - paste whatever you have.
- What's the difference between Readable and Strict cleaning?
- Readable is the default and favors keeping your log easy to debug - it skips a few higher-noise pattern types (like generic long hex/base64 strings, or region-specific ID formats such as Aadhaar/PAN) that have a higher chance of false-positives. Strict mode also enables those patterns for a more aggressive sweep before sharing with an external party.
- Can I get the original value back after masking?
- Yes. Every detected value appears in the mapping table below the output with three modes: Mask (default), Token (a stable placeholder like [EMAIL_1]), and Revert (puts the real value back). Switching modes updates the output instantly - no need to re-run Sanitize.
- What are placeholder tokens and why would I use them?
- A placeholder token like [EMAIL_1] or [JWT] tells the reader what kind of value was removed without showing the value itself - useful when you want the cleaned log to explain what changed. Use the Token action on any row of the mapping table, or Placeholder All to apply it everywhere at once.
- How do custom rules work, and are they saved?
- Add a Label, the exact text or a regex pattern to hide, and a replacement string in the Custom Rules panel. Rules are saved to this browser's localStorage automatically, so they're remembered next time you visit. Export them to a JSON file before clearing browser data or switching devices, then Import on the new browser. Regex rules run locally in a background thread with a 15-second limit: if a pattern backtracks catastrophically (nested quantifiers such as (a+)+ are the usual cause), the run is stopped with an error, nothing is sanitized, your input is kept, and you can simplify or disable the pattern.
- Will sanitizing break my ability to debug the log?
- That's the goal - Log Sanitizer never touches timestamps, HTTP methods, status codes, stack traces, error messages, hostnames used for troubleshooting context, line numbers, or thread names. Only values matched by an enabled rule (or a custom rule you defined) are replaced.
- Can I upload a file instead of pasting text?
- Yes - use the Upload File button on the input panel to load a .log, .txt, or .json file (up to 10MB) directly into the editor, then click Sanitize.
- Is Log Sanitizer free to use?
- Yes, completely free, with no sign-up, no usage limits, and no premium tier. Since everything runs in your browser, there's no server cost tied to how much you use it, so it stays free.
- What happens to real secrets that were exposed in a shared log?
- Treat any real key, token, password, or cookie that appeared in a log as exposed, even after you sanitize the copy you're sharing. Rotate it in the actual system it belongs to - sanitizing a shared copy doesn't undo prior exposure of the original.