Firefox .jsonlz4 -> .json Converter

Firefox stores some data in .jsonlz4 files compressed with LZ4. The file format has a custom data header - because on introduction no file standard was established yet.

This tool can decompress such .jsonlz4 files like sessionstore.jsonlz4 in the profile directory, or previous.jsonlz4, recovery.jsonlz4, upgrade.jsonlz4 in the profile sessionstore-backups directory.

No data is transferred to the server or third parties. This tool executes entirely client-side in the web browser.