Defog — Auto Text & Word Replacer

Automatically replace text, words, UUIDs, and patterns with readable labels on any website. Open source.

Defog automatically replaces text on every webpage you visit. Map UUIDs, IDs, hashes, codes, or any text pattern to a human-readable label — and never squint at a raw identifier again. Create a mapping once, and Defog replaces every occurrence across every site you visit. Replacements survive page navigation, dynamic content updates, and single-page app re-renders. Your data never leaves your browser. All mappings are stored locally. Fully open source: https://github.com/ayoung19/defog-extension Who is it for? Developers & DevOps Replace UUIDs, API keys, commit hashes, container IDs, and database row IDs with meaningful names across dashboards, logs, and admin panels. Support & Operations Map ticket IDs, customer IDs, and order numbers to names or descriptions so you can scan queues and dashboards faster. QA & Testing Turn opaque test data and environment identifiers into readable labels while reviewing test results or staging environments. Analysts & Data Teams Replace encoded dimension values, experiment IDs, or feature flag keys with plain English on analytics dashboards. Students & Language Learners Swap vocabulary words, abbreviations, or foreign terms with translations or definitions as you read. Content & Well-being Replace distracting, triggering, or unwanted words with alternatives as you browse. Anyone Nicknames for friends, inside jokes, or just making the internet a little more fun. Key Features - Instant text replacement across all websites - Works on dynamic pages — survives React re-renders, SPA navigation, and DOM mutations - Simple popup UI — add a mapping in seconds - Global on/off toggle — pause all replacements with one click - Dark mode, light mode, and system theme support - Unlimited mappings — no caps, no paywalls - All data stored locally in your browser — nothing is sent anywhere - Fully open source Coming Soon - Replacement templates — control how replacements render (e.g. "Andy Young (ebbaf2eb…)" or just "Andy Young") - Hover tooltips — see the original text on hover without replacing it - Import & export — share mapping sets with teammates - Site-specific rules — apply mappings only on certain domains - Regex pattern matching — match patterns instead of exact strings