JSONLZ4 file: How to open? The best software for opening jsonlz4 files

JSONLZ4

Mozilla Firefox compressed bookmark backup

File type: Backup file

Files with jsonlz4 extension are in most cases compressed bookmark backup files from Mozilla Firefox internet browser.

What is jsonlz4 file?

File type category:
Backup file

Date updated: June 27, 2025

File extension jsonlz4 is mainly associated with Firefox, a web browser for Microsoft Windows, Mac and Linux operating systems.

The .jsonlz4 file stores backup of bookmarks in JSON file (JavaScript object notation) format and uses data compression.

Firefox automatically creates 5 backup files, and these backups are stored in the bookmarkbackups folder inside the user profile folder.

On Microsoft Windows the usual location for the profile folder is:

C:\Users\"Windows login/user name"\AppData\Roaming\Mozilla\Firefox\Profiles\xxxxxxxx.default\

xxxxxxxx is a string of random characters, the second half of that part of the folder name is normally .default but may be something else.

You can use export/import (HTML) or backup/restore (JSON) in the Bookmarks Manager to create a backup or restore the bookmarks.

You can convert and recovert .jsonlz4 files back to HTML format.

Suggested software to open jsonlz4 file:

Associated software actions with the jsonlz4 file

JSONLZ4