# browser-extension

One tool for intercepting, mocking, and replaying HTTP — acquired by BrowserStack

Requestly is a BrowserStack-backed API client, HTTP interceptor, mock server, and session replay tool for frontend and QA teams. Its current product is commercial/API-client led, while the legacy interceptor/open-source code is AGPLv3. The free plan covers individual workflows, and Pro lists at $12/user/month monthly or $9/user/month annually for collaborative QA and frontend debugging teams.

Google Chrome Labs visual design tool for editing live web pages

VisBug is a Chrome Labs browser extension that lets developers and designers edit live web pages visually. It provides tools for moving, resizing, and styling elements directly on the page with point-and-click interaction. Features include margin and padding visualization, typography editing, color modification, and accessibility inspection without touching code or opening DevTools.

All-in-one browser DevTools extension for web developers

Hoverify is a browser extension that consolidates essential web development tools into a single overlay interface. It provides element inspection with CSS details, responsive design testing, accessibility checking, color picking, screenshot capture, and asset downloading. Activated by hovering over any webpage element, it provides instant development context without opening browser DevTools.

Open-source library for generating synthetic tabular data

Synthetic Data Vault (SDV) is an MIT-backed open-source Python library for generating synthetic tabular, relational, and time-series data. It learns statistical patterns from real datasets and produces synthetic versions that preserve distributions, correlations, and referential integrity. Supports single-table, multi-table, and sequential data with built-in privacy and quality metrics.

AI localization engine for software and docs

Lingo.dev is a Y Combinator F24-backed AI localization engine that automates translation of software interfaces and technical documentation into multiple languages while maintaining technical context. It preserves code variables, formatting tokens, and technical terminology that generic translation tools mangle, solving the global reach problem for developer-facing products and documentation.

Open-source secrets management platform

Infisical is an open-source secrets management platform with 16K+ GitHub stars for syncing environment variables and secrets across teams, CI/CD pipelines, and infrastructure. Features end-to-end encryption, automatic secret rotation, dynamic secrets, access controls with audit logs, and native integrations with AWS, GCP, Azure, Kubernetes, Docker, GitHub Actions, and Vercel. Replaces scattered .env files with a centralized, encrypted secrets store accessible via dashboard, CLI, SDK, or API.

Heads-up display plugin for Claude Code

Real-time visibility layer for Claude Code sessions that surfaces context window usage, active tools, token consumption, and task status directly in your terminal. Turns the opaque agentic loop into a transparent, monitorable process. Particularly useful during long-running agent sessions where understanding resource consumption and progress helps you decide when to intervene, redirect, or let the agent keep working.

Spec-driven development for AI coding assistants

OpenSpec is an open-source spec-driven development framework by Fission-AI for AI coding assistants. It adds a lightweight spec layer so developers and AI agents agree on what to build before any code is written. OpenSpec organizes changes in dedicated folders for proposals, specs, design docs, and tasks, and works across 21+ AI coding tools including Claude Code, Cursor, Windsurf, Continue, Gemini CLI, GitHub Copilot, and Amazon Q — bringing structured planning to agentic development.

Google's Core Web Vitals extension

Google's official Chrome extension for measuring Largest Contentful Paint, Interaction to Next Paint and Cumulative Layout Shift on the current page in real time. Combines local measurements with field data from the Chrome UX Report so developers can see how their lab numbers compare to real user experience. Reached end-of-life in January 2025 as its functionality shipped into the Chrome DevTools Performance panel.

Website technology lookup

Web technology profiler that identifies the frameworks, CMS, analytics, advertising, payment and hosting tools powering any public website. The database tracks 113,000+ internet technologies across 673 million domains, and the browser extension surfaces the full stack of whichever page you are viewing with a single click. Essential for competitive research, sales prospecting, compatibility checks and due diligence.

Developer news aggregator

Curated developer news platform that replaces your browser's new tab with a personalized feed of technical articles, releases and discussions drawn from 1,300+ engineering sources. Smart ranking surfaces content that matches the languages and tools you follow, while Squads let specialized communities discuss frameworks, careers and releases in the open. The fastest way to stay current without building and maintaining a private RSS habit.

Hundreds of GitHub UI enhancements

Open-source browser extension with hundreds of small UX improvements to GitHub: cleaner diffs, one-click PR merging, reaction avatars, linkified commit SHAs, and much more. Fixes dozens of long-standing GitHub UI annoyances that power users encounter daily, making the GitHub web experience feel polished and efficient without waiting for official feature updates.

GitHub code navigation sidebar

Browser extension that adds a file tree sidebar to GitHub repositories for easy code navigation. Browse files and folders without leaving the current page, with support for private repos, pull request code review navigation, file search, bookmarks, and theming. Works with GitHub Enterprise. Available for Chrome, Firefox, Safari, and Edge. Essential for navigating large GitHub repos without cloning. Freemium with Pro features for advanced code review and multiple GitHub accounts.

Pretty-print JSON in the browser

Open-source browser extension that automatically pretty-prints JSON responses in the browser tab. Supports collapsible nodes, syntax highlighting, and raw/formatted toggle. Essential developer tool for anyone who works with APIs regularly, turning unreadable JSON blobs into navigable, color-coded trees that make debugging API responses significantly faster and less error-prone.

Time-travel debugging for Redux

Browser extension for inspecting and debugging Redux state management in React applications. Features time-travel debugging to replay actions step-by-step, state diff viewer showing exactly what changed, action log with payload inspection, state import/export, and ability to dispatch actions manually. Supports Redux Toolkit and legacy Redux. Available for Chrome, Firefox, and as a standalone Electron app. Essential for debugging complex Redux state flows in production and development.

Identify web technologies

Wappalyzer is a technology detection service that identifies the tech stack behind any website — frameworks, CMS, analytics, CDNs, payment processors, and 2,500+ other technologies. Available as a browser extension (Chrome, Firefox, Edge), API, CLI, and bulk lookup service. Useful for competitive analysis, sales prospecting, and lead enrichment. Founded 2009 by Elbert Alias, remains independent and bootstrapped — free extension plus paid API and enterprise tiers.

Debug Vue.js applications

Official browser DevTools extension for Vue.js providing deep inspection of component trees, reactive state, props, events, and slots. Includes Pinia/Vuex store debugging with time-travel, Vue Router inspection, performance timeline, and component highlighting. Works with Vue 2 and Vue 3. Available for Chrome and Firefox with standalone Electron app. Essential for debugging reactivity and understanding component hierarchies in Vue applications.

Inspect React component trees

Official browser extension by Meta for inspecting and debugging React component trees, props, state, hooks, and context in real-time. Features component highlighting on hover, profiler for measuring render performance and identifying bottlenecks, and component search/filtering. Supports React 16+ including Suspense, error boundaries, and concurrent features. Available for Chrome and Firefox. Essential for debugging re-renders, state management issues, and understanding component hierarchies.