Tools for developers

A browser-based simulator for Arduino, ESP32, STM32 and Raspberry Pi Pico projects: wire parts on a virtual breadboard, run your firmware and even connect a simulated ESP32 to Wi-Fi. Great for learning before your board arrives and for sharing a reproducible project when you ask for help. Free plan available.

• Testing

Project Jupyter's free, open source environment for notebooks, code and data. You run code a cell at a time, see tables and charts right under it, and keep your reasoning in Markdown beside the code, which is how most data analysis is explored and shared. Installs with one pip command.

• AI
• Programming
• Machine learning

CyberChef, built and maintained by GCHQ, is a free browser-based tool for encoding, decoding, encrypting, compressing and generally transforming data through a drag-and-drop chain of small operations, nicknamed 'the Cyber Swiss Army Knife'. It runs entirely in the browser with no server-side processing of your data, which matters when the data you are working with is sensitive. With nearly 36,000 GitHub stars, it is one of the most widely used free utilities of its kind.

• Programming
• Web
• DevOps

GitHub's official command-line tool, `gh`, for pull requests, issues, repositories, releases and Actions runs from the terminal. It makes the everyday GitHub workflow faster, handles authentication for Git, and is easy to use in scripts.

• Dev tools
• DevOps

Gemini Notebook, called NotebookLM until July 2026, is Google's research notebook that answers questions using only the sources you add, such as PDFs, slides, notes, websites and videos, with citations back to the passage used. Students use it to study course material and turn it into study guides, quizzes, flashcards and audio or video overviews. It is free with daily limits, and higher limits come with Google AI plans.

• AI

A workflow automation platform, similar in spirit to Zapier, that you can self-host for free or use as a paid cloud service. You connect apps and APIs on a visual canvas, drop into JavaScript or Python when needed, and build AI agent workflows with language models and tools. It suits developers and technical students who want powerful automation with full control over their data and costs.

• AI
• DevOps
• Programming
• Web

GitHub Copilot is GitHub's AI coding assistant. It completes code as you type, answers questions in chat, runs as an agent that edits files and runs commands in your editor, and can take on issues as a cloud coding agent that opens pull requests. It works inside VS Code, Visual Studio, JetBrains IDEs, Xcode, Neovim and more. There is a free tier, and verified students get the Copilot Student plan at no cost.

• AI
• Dev tools

Cursor is an AI code editor built on VS Code, with agents that read your whole repository, plan changes across many files, run commands and review pull requests. It suits developers and students who want AI help inside their editor rather than a separate chat window. The free Hobby plan has limited agent use; serious daily use needs the $20 Pro plan or higher.

• AI
• Dev tools

Microsoft's free code editor, built on open source, and used by most developers for almost every language through its extension marketplace. It includes a debugger, Git integration, an integrated terminal and, more recently, AI agent features through GitHub Copilot with a free tier. Learn its debugger early instead of scattering print statements through your code.

• Dev tools

Postman is an API platform whose core is an API client: you send HTTP requests by hand, save them in collections, use variables and environments, write simple tests on responses, and import OpenAPI descriptions. The free plan covers one user and is enough for learning and personal projects; paid plans add collaboration and more usage. It suits backend and frontend developers who need to explore, debug and document APIs, and it is a tool many teams expect you to know.

• Web
• Backend

A free browser tool for writing, testing and debugging regular expressions. It highlights matches live against your test text, explains every token in plain English as you type, and includes a step-by-step debugger, a quick reference and a code generator. It suits anyone who copies patterns from the web without fully understanding them, or who needs to work out why a pattern fails or runs slowly.

• Programming
• Web

A paid, human review of your resume by experienced engineers and hiring managers from large technology companies, returned in three to five business days with line-by-line suggestions, proposed rewrites of bullet points and applicant tracking system advice. It suits engineers whose resume is already reasonably solid and who want detailed feedback from people who screen engineering resumes for a living before a job search.

• Career
• Job search

A compensation site built from self-reported and verified salaries by company, level and location, with level mappings that let you compare titles across employers. It covers tech and a growing set of other industries, plus internships and US visa salary data. Free to browse; paid negotiation coaching is also offered. Walking into a negotiation without this kind of data means negotiating blind.

• Career
• Job search

Can I use shows browser support tables for front end web features (HTML, CSS, JavaScript APIs and more), with global and per country usage percentages from StatCounter rather than a simple yes or no, plus notes on partial support and known bugs. It answers "can I ship this feature yet?" in seconds, for any front end developer deciding what is safe to use.

• Web
• Frontend
• Programming

A free, open source virtual whiteboard with a hand-drawn look that opens instantly in the browser with no account. You can sketch diagrams, share a live collaboration link, and export to PNG, SVG or JSON. It is widely used for system design interviews, architecture discussions and quick explanations. Practising your diagrams here before an interview means you spend the round thinking, not hunting for the arrow tool.

• System design

Hugging Face's documentation for safetensors, a simple file format for model weights that cannot run code when loaded, unlike Python pickle files. Short, practical and the first fix to know for model file supply chain risk.

• AI
• Machine learning
• Programming

The Home Office's public list of every organisation licensed to sponsor workers in the UK, published on GOV.UK as a CSV file and updated often. Before you spend weeks on an application, check that the employer is on it, licensed for the Skilled Worker route and holds an A rating.

• Career
• Job search

An open source framework for evaluating large language models, built by the UK AI Security Institute. Datasets, solvers, agents, tools and scorers compose into repeatable evals, with sandboxed tool execution, a log viewer and a collection of 200+ ready-made evaluations. A serious tool for safety and security evals of models and agents.

• AI
• Programming
• Testing

A hosted document parsing service from the LlamaIndex team for hard documents: scanned PDFs, forms, tables, charts, slides and spreadsheets, across 130+ formats. It returns Markdown, text or JSON, and the same API key covers extraction to a schema, classification and managed indexing. Billed in credits, with a free monthly allowance.

• AI
• Backend

An AI avatar video platform: write a script and a digital presenter speaks it with lip-sync, in more than 175 languages and dialects according to HeyGen. Used for training, product explainers and translated videos. Custom avatars of real people require their consent.

• AI

NVIDIA's open source toolkit for adding programmable guardrails to LLM apps: input, dialog, retrieval, execution and output rails, with built-in checks such as jailbreak detection and content safety. A hands-on way to learn where guards sit in an app and why each one is only a layer.

• AI
• Programming

An open source toolkit, started at Microsoft and now community maintained, that detects personal data such as names, phone numbers and card numbers in text and images, then redacts, masks, replaces, hashes or encrypts it.

• AI
• Security
• Programming

A popular video editor for short vertical video on phone, desktop and web, with auto captions, templates, text-to-speech and many AI tools built in. Fast for Reels, TikTok and Shorts. Not available in India, where it is blocked.

• AI

Google's AI filmmaking tool built on its Veo video models. Veo 3.1 makes short clips with generated sound, supports reference images for consistent characters and styles, first and last frame control, and marks every video with a SynthID watermark.

• AI