fq

fq [options] [query] [file]

fq is a tool for inspecting binary files using a jq-like query language. It can decode and query over 100 different binary formats including MP4, FLAC, JPEG, PCAP, ELF, and many more.
The tool provides a REPL with autocomplete, allowing interactive exploration of binary structures. It's useful for debugging, reverse engineering, and understanding file formats.

-d, --decode FORMAT

Decode as specific format

Start interactive REPL

Use null as input value

Output raw strings

Compact output (no pretty print)

Display help and exit

Display version and exit

Basic inspection:

$ fq . file.mp4

$ fq '.meta.moov.tracks[0].mdia.minf.stbl.sample_descriptions[0].width' video.mp4

$ fq -d raw '.[0:10]' file

$ fq -h

Large files may consume significant memory. Some formats have incomplete support. Binary data output may require terminal with proper encoding support. Complex nested queries can be slow.

fq was created to bring the power of jq to binary data, making it easier to inspect and understand binary file formats without specialized tools.

[jq](https://stedolan.github.io/jq/), [xxd](https://linux.die.net/man/1/xxd), [hexdump](https://linux.die.net/man/1/hexdump), [binwalk](https://github.com/ReFirmLabs/binwalk)