Curated list · 10 picks
Best Chrome extensions for developers
The AltFTool extensions we reach for while building and debugging: test an API, keep snippets, check redirects, read a site's stack and pull design tokens.
Latest change to a listed extension: Jul 21, 2026
- 1
API Tester Pro
Send REST, GraphQL and WebSocket requests without opening a desktop client.
API Tester Pro is a powerful browser extension for testing REST, GraphQL, and WebSocket APIs in one place. It allows developers to send requests, analyze responses, and manage configurations easily. With a clean interface and local storage, it streamlines API workflows without relying on external tools or services.
- 2
Code Snippet Manager
Keep reusable code within one click of any tab.
Code Snippet Manager is a fast, lightweight, and privacy-focused Chrome extension that helps developers save, organize, search, and reuse code snippets directly from the browser. Whether you're a frontend developer, backend engineer, or student, this tool eliminates repetitive typing and keeps your most-used code just one click away.
- 3
DataFormat Pro
Format and validate data payloads in the browser.
Format, validate, and convert structured data instantly with a powerful browser-based tool. Improve readability, detect errors, and manage multiple data formats with a fast and developer-friendly interface.
- 4
Tech Detector Pro
See which frameworks and services a site runs on.
Tech Detector Pro is a powerful browser extension that reveals the technology stack behind any website instantly. It detects frontend, backend, CMS, analytics, and more with a single click. Designed for developers and analysts, it provides organized insights while keeping all processing local and fully privacy-focused.
- 5
Deep Redirect Trace
Follow every hop of a redirect chain while debugging links.
Analyze redirect chains, audit on-page SEO, and monitor site health in real time. Powerful all-in-one tool for developers and marketers with fast, local, and privacy-focused performance
- 6
GitIgnore Pro
Generate a .gitignore for your stack in seconds.
GitIgnore Pro is a smart and lightweight tool to generate .gitignore files instantly based on selected technologies. It offers presets, real-time preview, and easy export options. Designed for developers, it simplifies repository setup while keeping everything fast, clean, and fully local without any data tracking or external dependencies.
- 7
README Generator
Draft a clean README from a few fields.
Create professional and well-structured README files for your projects with ease. This extension helps developers generate clean documentation using customizable templates, markdown support, and real-time preview. Improve project presentation, maintain consistency, and save development time by quickly producing clear, organized, and visually appealing README files directly from your browser.
- 8
Design Token Extractor Pro
Pull colours, type and spacing tokens from a live page.
Design Token Extractor helps developers and designers instantly extract design tokens from any webpage. With a single click, the extension analyzes the current page and identifies key styling elements such as colors, typography, spacing, and layout properties. It reads computed styles from visible elements and organizes them into a structured format, making it easier to understand design systems, maintain consistency, and reuse styles across projects. This tool is especially useful for frontend developers, UI/UX designers, and anyone working with design systems or component libraries. All processing is performed locally in the browser and only runs when the user actively triggers the extension.
- 9
CSS Specificity
Settle which CSS selector wins without guesswork.
CSS Specificity Calculator is a simple and efficient tool designed to help developers understand how CSS selectors are prioritized by the browser. This extension allows users to input any CSS selector and instantly calculate its specificity value by breaking it down into inline styles, IDs, classes, attributes, and element selectors. It helps developers debug styling issues, avoid conflicts, and write more predictable and maintainable CSS. The tool works in a clean and minimal interface, focusing only on calculating and displaying specificity results without modifying any web pages or accessing unnecessary data.
- 10
Website Preview Pro
Generate a live visual preview of any URL.
Website Preview Pro is a fast and modern Chrome extension that allows users to instantly generate visual previews (live screenshots) of any website directly from the browser. With a simple and clean interface, users can enter any URL or preview their current tab to view how the website looks without opening it in a new tab. The extension supports both desktop and mobile preview modes, enabling quick responsive checks.
About this list
What is the best for developers Chrome extension?
Our top pick is API Tester Pro: Send REST, GraphQL and WebSocket requests without opening a desktop client. The rest of the list is ranked by how often our editors reach for each one.
How was this list chosen?
AltFTool editors picked and ordered these from the extensions we publish, based on what each one does and how polished it is. It is not based on paid placement or user review counts.
Are the extensions on this list free?
Yes. Every extension here is free to install from the Chrome Web Store and needs no AltFTool account.
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