If you are searching for the best AI for coding, you have probably met dozens of names that all promise to multiply your speed. The truth is that these tools work in three very different categories, and comparing Copilot with Devin is like comparing a bicycle with a truck. The right question is: which tool fits the kind of work I do?
Quick answer: which one for whom#
- You spend most of your day inside the editor: Cursor or GitHub Copilot.
- You want to hand large, multi-step tasks to an agent: Claude Code or Codex.
- You do not want to be locked into one company or model: Cline or Aider.
- You want to build and publish an app without installing anything: Replit.
- Your team gives well-defined tasks to an autonomous agent in the cloud: Devin.
If the difference between a chat assistant, autocomplete and an agent is still fuzzy, start with AI tools for programming: from chat to agents inside the editor.
Comparison table#
| Tool | Type | Pricing model | Main strength | Non-English prompts |
|---|---|---|---|---|
| Claude Code | Agent in terminal, editor and web | Paid | Long, multi-step work on large codebases | Good |
| Cursor | Full editor based on VS Code | Freemium | Smooth multi-file editing and model choice | Good |
| GitHub Copilot | Extension for many editors | Freemium | GitHub integration and support for almost any editor | Good |
| Codex | Agent in terminal, editor and cloud | Freemium (with a ChatGPT account) | Parallel tasks in the cloud | Good |
| Windsurf | Editor with built-in agent | Freemium | Fast autocomplete | Good |
| Cline | Open-source agent extension | Free + model cost | Full control, you approve every step | Basic |
| Aider | Open-source terminal tool | Free + model cost | Every change committed to git automatically | Basic |
| Replit | Online environment with an agent | Freemium | From idea to published app with no setup | Good |
| Kiro | Agentic environment from AWS | Freemium | Spec-driven workflow | Basic |
| Devin | Autonomous cloud agent | Paid | Works independently up to a pull request | Basic |
The last column is about understanding instructions and explanations in languages other than English; code and commit messages usually stay in English in all of these tools.
Editors and in-editor assistants#
Cursor#
Cursor is an editor built on top of VS Code with AI at its core. Multi-line autocomplete, chat with the whole project and an agent that edits several files at once make for a smooth experience. It accepts VS Code extensions and settings, and you can choose between models from different companies. The downside: agent-heavy work burns through credits quickly, and if you are used to another editor, you have to switch.
GitHub Copilot#
Copilot is for developers who do not want to change editors. It works everywhere from VS Code to JetBrains IDEs, integrates with GitHub issues and pull requests, and its cloud agent can turn an issue into a ready change. It has a free tier, and students can get the full version free. In whole-project understanding and multi-file edits, dedicated AI editors are sometimes ahead.
Windsurf#
Windsurf is another VS Code-based editor with a built-in agent and fast autocomplete. Its ownership has changed and it is now also offered as Devin Desktop, which makes its future direction and pricing less predictable.
Coding agents#
Claude Code#
Claude Code reads the whole repository, edits files, runs commands and tests, and tries again when something breaks. For big jobs such as implementing a complete feature, migrating a framework or fixing a bug with real execution, it is one of the strongest options. You can tailor it with a project instructions file and MCP connections. It has no free tier and works only with Anthropic models.
Codex#
Codex is OpenAI's coding agent. It runs in the terminal (an open-source CLI), in editors, in a desktop app and in the cloud. The cloud version runs tasks in isolated, parallel environments and hands back changes ready to merge. It needs no separate purchase and works with a ChatGPT account, but the free quota is small for real work.
Kiro and Devin#
Kiro from AWS first writes requirements, a design and a task list, and only then writes code. That structure helps on serious projects but feels heavy for small tasks. Devin takes a task and works in its own virtual machine until a pull request is ready; it suits teams with well-defined, repeatable tasks, not personal projects or vague requirements.
Open-source tools: Cline and Aider#
Cline is a VS Code extension that works like an agent but moves forward only with your approval at each step. Aider runs in the terminal and commits every change to git with a clear message, so undoing is easy. Neither is tied to a specific model: both work with an API key from any provider or even a local model. In return, the initial setup takes some effort, and the quality depends on the model you choose.
Replit: from idea to a published app#
Replit is a complete development environment in the browser. You describe what you want to its agent; it writes code, creates a database, runs and tests the app and publishes it. It is great for prototypes and small projects. Apps depend on Replit's infrastructure, and the agent sometimes gets stuck in a fix-the-error loop that eats credits.
How to choose#
- Decide where you work: if you do not want to change editors, use Copilot or an extension such as Cline. If you are open to a new editor, try Cursor or Windsurf.
- Size the task: line and function completion belongs to an assistant; a full feature or changes across dozens of files belongs to an agent.
- Think about code privacy: most of these tools send code to their servers for processing. If your code is confidential, read the privacy terms or consider an open-source tool with a local model.
- Count the real cost: agent work uses up quotas fast. Test for a week on real tasks before you decide.
- Try two tools side by side: many developers use an AI editor and an agent together.
To compare the chat models themselves for coding, see ChatGPT vs Claude vs Gemini: which one for what.
Common mistakes#
- Accepting changes without reading them: agents sometimes make oversized or wrong changes. Read every diff; a structured approach is in AI code review: what it finds and what it misses.
- Granting unlimited permissions: an agent that runs commands can damage files or data. Keep permissions narrow and work on a separate branch. Details in coding agents: when AI changes the code itself.
- Describing errors poorly: however strong the tool, an incomplete error message gets a guessed answer. See what to send in debugging with AI.
- Choosing by hype: a tool that is popular on social media is not necessarily a fit for your language, framework or workflow.
- Having no tests: without automated tests you cannot tell whether an agent broke something.
Some of these services restrict access by country, and availability can change.
Summary#
- The "best" tool depends on the job: an in-editor assistant, an autonomous agent or an online environment.
- Cursor and Copilot for daily editor work; Claude Code and Codex for large, multi-step tasks.
- Cline and Aider are open source and model-agnostic; Replit is for building and shipping fast.
- Prices and quotas change often; check each tool's official site.
- Review every agent change, keep permissions narrow and keep tests in place.
