FREE FIREFOX CONFIGURATION TOOLKIT

Firefox CFG tools. Simple, secure, online.

Edit, encode, decode, validate, and generate Mozilla CFG files. Five focused tools for Firefox AutoConfig.

Decode a CFG file →Explore all tools ↗
Free to useNo sign-upFocused Firefox tools
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Decode your Mozilla CFG file instantly

Upload a Firefox mozilla.cfg file or paste its contents. Decode with legacy byte shift minus 13, or inspect plain text without conversion.

Maximum file size: 10 MB.

Processed locally in your browser. Nothing is uploaded.
ALL-IN-ONE TOOLKIT

Everything you need for CFG files

Five focused utilities for real Firefox AutoConfig workflows.

Mozilla CFG DecoderDecode Firefox mozilla.cfg files using byte shift 13 or plain-text mode.Open tool →Mozilla CFG EncoderEncode Firefox AutoConfig scripts or export unshifted CFG files.Open tool →Online CFG EditorEdit configuration scripts with a browser-based editor.Open tool →CFG ValidatorRun preliminary structural checks on AutoConfig scripts.Open tool →AutoConfig GeneratorGenerate matching mozilla.cfg and autoconfig.js files.Open tool →

New to Firefox AutoConfig?

Learn how mozilla.cfg, autoconfig.js, and locked preferences work together.

Read the setup guide →
GUIDES

Practical Firefox AutoConfig guides

↗   How to Set Up Firefox AutoConfig↗   How to Decode a Mozilla CFG File↗   Firefox lockPref vs defaultPref

Frequently asked questions

What is Mozilla CFG byte shift 13?

Firefox AutoConfig files may use reversible byte shifting by 13. This is obfuscation, not encryption. The configuration can also be configured without shifting.

Does the tool decode all CFG formats?

No. Many games, servers and applications use the CFG extension. This specific tool supports Firefox AutoConfig byte shifting only.

Are files stored?

No. The application sends the input to the conversion server, processes it in memory and does not persist file contents. Do not submit secrets or sensitive configuration files.