How to open Firefox bookmark backup files

For reasons incomprehensible to me, Firefox is using non standard jsonlz4 file format to store bookmark backups. You can forget about standard console based utilities to extract its contents as I have already tried this without any success. It is a huge let down.

The solution is to use C decompress tool for mozilla lz4json format application by Andi Kleen.

Compilation process

Install required dependencies.

$ sudo apt-get install build-essential liblz4-dev

Clone git repository.

$ git clone

Change working directory.

$ cd lz4json

Compile application from source code.

lz4json$ make


Pass a compressed bookmark backup file as an argument to application, uncompressed data will be printed to stdout.

lz4json$ ./lz4jsoncat ~/.mozilla/firefox/profile.default/bookmarkbackups/bookmarks-2015-07-30_20.jsonlz4 


Milosz Galazka's Picture

About Milosz Galazka

Milosz is a Linux Foundation Certified Engineer working for a successful Polish company as a system administrator and a long time supporter of Free Software Foundation and Debian operating system.

Gdansk, Poland