Extract text from JSONLZ4 files
To convert your JSONLZ4 file to another format, you need Mozilla Firefox or other Compressed software.
To convert other file formats to the "LZ4 Compressed JSON" file type, you need software like Mozilla Firefox or a similar tool.
.JSONLZ4 files are specialized, compressed data containers used by Mozilla Firefox to store critical user profile information, such as sessionstore.jsonlz4 (open tabs), bookmark backups, and search engine configurations. While the underlying content is standard JSON, Mozilla applies LZ4 compression with a proprietary mozLz40 header to reduce disk usage and improve startup performance.
The Problem: Because of the non-standard mozLz40 header, generic LZ4 decompressors (like standard command-line tools or archive managers) usually cannot open these files, returning "invalid format" errors. Users trying to recover lost tabs, migrate bookmark data, or manually edit search engines find these files inaccessible without custom Python scripts. You cannot simply open them in a text editor like Notepad or VS Code to view the contents.
The Solution: To access the data, the file must be decompressed and stripped of its custom header. The best approach is to convert .JSONLZ4 to standard JSON. This renders the text human-readable for forensic analysis, debugging, or manual recovery of session data. For general viewing, converting to TXT is also effective.
Convert.Guru analyzes your JSONLZ4 file, detects the exact format, and lets you read the text inside.
Users also converted BAKLZ4, LZ4, JSON, SAFE BROWSING COOKIES, VISITED LINKS, SQLITE, TXT, CSV, HTML, BAK, DRP, EXE and RFA files.
If you want to convert JSONLZ4 file to JSON, ZIP, RAR, 7Z, TAR, GZ, BZ2, XZ, LZMA, CAB, ACE or ARJ, you can use Mozilla Firefox or similar software from the "Compressed Browser Data" category. In the File menu, look for Save As… or Export….
To convert XXE, 7Z, Z, PAK, LHA, DEB, UUE, TAR, LZH, ZIP, PKG or RAR files to JSONLZ4, try Mozilla Firefox or another comparable tool in the "Compressed Browser Data" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our JSONLZ4 converter.