// comparison
AI coding assistants compared
Most AI coding assistants now do the same core job: read your code, edit files and run commands. They differ mainly in where they run, how they read project rules, what’s free and what the first paid plan costs. The table below compares twelve of them using only facts from each vendor’s own pages.
Checked on . Prices are in US dollars for individuals unless noted, before tax. Pricing changes often, so confirm on the linked page before you buy. "Not verified" means the vendor's pages didn't state it clearly when checked.
| Tool | Where it runs | Project rules file | Free option | Entry paid price | Bring your own model/key | Open-source license | Source (as of 2026-10-16) |
|---|---|---|---|---|---|---|---|
| GitHub CopilotGitHub | IDE extensions, Copilot CLI and the Copilot app (all plans include the CLI and app) | .github/, .github/ (with applyTo globs), AGENTS.md; or a single root CLAUDE.md or GEMINI.md | Yes: Copilot Free, limited to 2,000 inline completions per month; free for verified students | Pro: $10/month. Pro+: $39/month. Business: $19 per seat/month | Not verified | None found | |
| CursorCursor | Desktop app, CLI, cloud agents | .cursor/ project rules, or AGENTS.md for plain Markdown | Yes: Free plan with limited AI usage | Plus: $8/month (Grok models only). Premium: $30/month. Third-party models billed separately by usage | Not verified | None found | Cursor pricing Cursor Docs: rulesCursor's pricing page now lists combined Cursor and Grok plans with a shared usage pool. |
| Claude CodeAnthropic | Terminal CLI, VS Code and JetBrains extensions, desktop app, web | CLAUDE.md (can also read a repository’s AGENTS.md) | No: not in the Free plan; included from Pro | Pro: $20/month, or $17/month billed annually | Yes: Anthropic Console (API) account; the CLI, VS Code and JetBrains also support third-party providers | None found | |
| OpenAI CodexOpenAI | Web, CLI, IDE extension, desktop app, iOS | AGENTS.md | Yes: ChatGPT Free, in the desktop app (subject to rollout) | Go: $8/month (desktop app). Plus: $20/month (web, CLI, IDE extension, iOS) | Yes: API key, billed at API prices (no cloud features) | Apache-2.0 (Codex CLI) | |
| Google AntigravityGoogle | Antigravity App, IDE, CLI, extensions and SDK | Not verified | Yes: individual plan at $0/month | Through Google AI Pro or Ultra (price not shown on the Antigravity page). Business via Google Cloud from $30 per seat/month | Not verified | None found | Google Antigravity pricingGoogle moved unpaid-tier Gemini CLI users to Antigravity CLI on June 18, 2026. |
| Gemini CLIGoogle | Terminal | GEMINI.md context files | No longer for unpaid users: replaced by Antigravity CLI on June 18, 2026 | Use with a Gemini API key (usage-based), Vertex AI or a paid Code Assist license | Yes: Gemini API key or Vertex AI | Apache-2.0 | |
| JunieJetBrains | Terminal CLI, JetBrains Air in IDEs, GitHub Action, GitLab CI/CD | AGENTS.md (listed as supported on agents.md); plans saved in .junie/plans | Yes: "Junie Lite", a free tier with no trial or card | Not verified | Yes: 10+ models via bring-your-own-key | None found | |
| Amazon Q DeveloperAmazon Web Services | IDE plugins and CLI | Not verified | Yes: perpetual Free Tier with monthly limits | Pro: $19 per user/month | Not verified | None found | |
| KiroAmazon Web Services | Kiro IDE, Kiro CLI, Kiro Web | .kiro/steering/ steering files; AGENTS.md supported | Yes: Kiro Free with 50 credits | Pro: $20/month (1,000 credits). Pro+: $40/month | Not verified | None found | |
| Windsurf / DevinCognition | Devin Desktop, CLI, Devin Cloud agents | AGENTS.md (Windsurf is listed as supported on agents.md) | Yes: Free plan with a light quota | Pro: $20/month. Max: $200/month. Teams: $80/month plus $40 per developer seat | Not verified | None found | Devin plans and pricing (redirect target of windsurf.com/pricing) AGENTS.md supported toolswindsurf.com/pricing redirects to devin.ai/pricing. |
| ClineCline | VS Code extension, JetBrains plugin, CLI, desktop app, SDK | .clinerules/ or .cline/rules/, AGENTS.md; also reads .cursorrules | Yes: open source; you pay your model provider | No subscription needed; costs depend on the model provider you connect | Yes: Anthropic, OpenRouter and many other providers | Apache-2.0 | |
| AiderAider (open source project) | Terminal | CONVENTIONS.md loaded with --read or read: in the config file | Yes: open source; you pay your model provider | No subscription; costs depend on the model provider you connect | Yes: works with most cloud and local LLMs | Apache-2.0 |
How to choose
Start from where you already work, then narrow by cost and policy:
- Where you code. If you live in VS Code or a JetBrains IDE, an extension (Copilot, Cline, Claude Code, Codex) keeps you in place. If you prefer the terminal, Claude Code, Codex CLI, Aider and the Copilot CLI all run there.
- What your company already pays for. A GitHub, Google Cloud or AWS agreement may already cover Copilot, Antigravity or Amazon Q Developer and Kiro, with admin controls your security team has approved.
- Model and data rules. If you must use a specific provider or keep code on your own infrastructure, look at tools that let you bring your own model or key.
- A real trial. Give two or three tools the same small, real task from your codebase, with the same project rules file, and compare the diffs.
What the columns mean
- Project rules file is where the tool reads standing instructions for your repository. See the glossary entry.
- Entry paid price is the cheapest individual paid plan the vendor lists. Usage limits differ widely between plans and aren't comparable across vendors.
- Open-source license shows the license on the tool's official GitHub repository. "None found" means no open-source license was published there or the client isn't open source.
Frequently asked questions
Which AI coding assistant is best?
There is no single best one. Pick by where you work (editor, terminal or browser), which models you're allowed to use, whether your team already pays for a platform such as GitHub or AWS, and price. Try two or three on the same real task from your own codebase before committing.
Do AI coding assistants share a common rules file?
Increasingly, yes. AGENTS.md is an open format that many tools read, including OpenAI Codex, GitHub Copilot, Cursor, Cline, Kiro, Junie and Windsurf. Claude Code uses CLAUDE.md and can also read AGENTS.md. Aider loads a conventions file you point it to.
Can I use an AI coding assistant with my own API key?
Several support it. Cline and Aider are open source and work with the model provider you choose. Codex, Gemini CLI and Junie accept API keys, and Claude Code works with an Anthropic Console account or supported third-party providers.
Are any AI coding assistants open source?
Yes. As of the date on this page, the OpenAI Codex CLI, Gemini CLI, Cline and Aider are published under the Apache-2.0 license on GitHub.
Sources
- AGENTS.md: a simple, open format for guiding coding agents. Lists the tools that support the AGENTS.md format