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Decompress Mozilla Firefox bookmarks backup files

dejsonlz4

Decompress Mozilla Firefox bookmarks backup files

Current Firefox bookmarks backup files are stored as non-standard file format based on lz4 compression. These files have a .jsonlz4 extension. Use dejsonlz4 to decompress them.

lz4.c and lz4.h at this repository are verbatim copies from the Mozilla repository as of 2016-05-12 (as currently used by Firefox) [1].

Usage:

Usage: dejsonlz4 [-h] IN_FILE [OUT_FILE]
   -h  Display this help and exit.
Decompress Mozilla bookmarks backup file IN_FILE to OUT_FILE.
If IN_FILE is '-', decompress from standard input.
If OUT_FILE is '-' or missing, decompress to standard output.
Note: IN_FILE is transferred to memory entirely before decompressing.
Decompression is also done in memory entirely before output.

Build:

  • gcc -Wall -o dejsonlz4 src/dejsonlz4.c src/lz4.c

Windows note:

  • dejsonlz4 on Windows does not support unicode path/file names at this time.

References:

  • Project page and source files: https://github.com/avih/dejsonlz4
  • Releases and binary builds for Windows: https://github.com/avih/dejsonlz4/releases

External resources:

  • Mozilla Firefox bug 818587 - Compress bookmark backups.
  • Mozilla Firefox bug 1209390 - Use standard lz4 file format instead of the non-standard jsonlz4/mozlz4.

[1] Mozilla's mercurial repo rev. c3f5e6079284: lz4.h and lz4.c