Best AI Coding Assistants (September 2026)

1

Windsurf

Top pick

windsurf.com

Best for Developers wanting agentic AI-assisted coding·Free trial

Windsurf is an AI-powered code editor built to support agentic software development workflows. It combines an integrated development environment with AI capabilities that can generate, edit, and refactor code across multiple files while maintaining awareness of project context. The tool offers chat-based interaction alongside autonomous task execution, allowing developers to delegate multi-step coding tasks. Windsurf suits individual developers and engineering teams looking for an AI-assisted coding environment that goes beyond simple autocomplete, integrating more deeply into the coding workflow than traditional code-completion plugins.

• Multi-file code generation
• Agentic task execution
• AI chat within IDE

2

GitLab Duo

gitlab.com

Best for Teams already using GitLab for DevSecOps

GitLab Duo is an AI-powered assistant built into the GitLab DevSecOps platform, offering code suggestions, a chat interface, code explanation, test generation, and vulnerability summarization within the development workflow. It integrates with GitLab's existing repository, CI/CD, and security scanning features, allowing suggestions and explanations to draw on project context. GitLab Duo is aimed at development teams already using GitLab for source control and pipelines who want AI assistance embedded alongside code review, planning, and security tooling rather than as a separate standalone tool.

• Code suggestions
• Chat-based code explanation
• Vulnerability summarization

3

JetBrains AI Assistant

jetbrains.com

Best for Developers using JetBrains IDEs

JetBrains AI Assistant is an AI coding tool built into JetBrains IDEs such as IntelliJ IDEA, PyCharm, WebStorm, and Rider. It provides code completion, in-IDE chat, code explanation, refactoring suggestions, test generation, and documentation writing, using both JetBrains' own models and third-party LLMs. Because it is embedded directly in the IDE, it has access to project context for more relevant suggestions. It suits developers and teams already working within the JetBrains ecosystem who want AI assistance without switching tools.

• In-IDE code completion
• AI chat with project context
• Code refactoring & test generation

4

Replit

Free plan

replit.com

Best for Students and small teams prototyping web apps

Replit is a browser-based development platform that combines a code editor, execution environment, and hosting in one workspace. It includes an integrated AI assistant that can generate, explain, and debug code across multiple programming languages, as well as help scaffold entire applications from natural-language prompts. The platform supports real-time collaborative editing and one-click deployment, removing the need for local setup. It suits students, hobbyist developers, and small teams looking to prototype, learn, or build web applications without configuring local development environments.

• AI code generation
• Browser-based IDE
• Real-time collaboration

5

Devin

cognition.ai

Best for Engineering teams exploring autonomous coding agents·Paid only

Devin, developed by Cognition AI, is an autonomous software engineering agent designed to independently plan and execute coding tasks. It can write code, debug errors, and run tests within its own sandboxed development environment, integrating with tools like GitHub and Slack. Rather than serving as an inline autocomplete assistant, Devin is positioned to handle longer, more complex engineering tasks with reduced human oversight, such as resolving bugs or implementing features end to end. It suits engineering teams exploring agentic automation for parts of their software development workflow.

• Autonomous task execution
• Sandboxed dev environment
• Tool integrations (GitHub, Slack)

6

Sourcegraph Cody

Free plan

sourcegraph.com

Best for Development teams with large codebases

Cody is an AI coding assistant developed by Sourcegraph that provides code autocompletion, chat-based question answering, and code generation within popular editors such as VS Code and JetBrains IDEs. It uses codebase context, including symbols and file relationships, to give more relevant suggestions and explanations for large or complex repositories. Cody supports multiple large language models and can be used for tasks like writing unit tests, explaining unfamiliar code, and refactoring. It is aimed at software development teams working with sizeable codebases who want context-aware AI assistance integrated into their existing workflows.

• Codebase-aware chat
• Code autocompletion
• Multi-LLM support