Pick a coding agent for your team
Start from the benchmarks, not the end
Public scores tell you which harness and model do well on a fixed set of tasks. They don't tell you how an agent works on your repository, with your tests and your conventions.
Run the same three tasks in your top two
Choose a bug fix, a small feature and a review you already know the answers to, and compare the diffs, the time and the cost under each plan.
Open Reason on the web or the Mac app
Sign in at reasonmachines.com, or download the Reason app for macOS from reasonmachines.com/download. Both open the same Sessions. Sending work to Reason needs a Pro or Max plan.
Switch the model and compare
Start a second Session on the same branch with a model from another provider, and ask it to review the first diff. Each Session shows the model and account it ran on.
Ranked by Artificial Analysis Coding Agent Index v2.0
| Rank | Agent and model | Index v2.0 | Cost per task |
|---|---|---|---|
| 1 | Claude Code, Claude Opus 5.5 (Max) | 62 | $11.42 |
| 2 | Codex, GPT-6 Astra | 55 | $7.04 |
| 3 | Grok Build, Grok 4.7 | 47 | Not read |
As listed on Artificial Analysis's comparison pages, checked Nov 2, 2026. Version 2.0 (October 2026) combines FrontierCode v1.1, Terminal-Bench 4.0 and SWE-Atlas-QnA-AA; its leaderboard renders in the browser, so we list only the entries we could read, and Claude Code also scores 59 on Sonnet 5.5 and 58 on Fable 5.1.
Terminal-Bench 4.0, top agent entries
| Rank | Agent | Model | Resolution rate | Date |
|---|---|---|---|---|
| 1 | Claude Code | Opus 5.5 (max) | 64.8% | Sep 22, 2026 |
| 2 | Claude Code | Sonnet 5.5 (max) | 61.8% | Sep 28, 2026 |
| 3 | Codex | GPT-6 Astra (max) | 58.2% | Sep 3, 2026 |
| 4 | Codex | GPT-6.1 Sol (max) | 58.2% | Sep 29, 2026 |
Terminal-Bench 4.0 has 66 tasks. The official leaderboard at tbench.ai renders client-side, so these rows are as published on Snorkel's mirror of it, checked Nov 2, 2026.
The rest, by what they're best for
| Agent | Best for | Price |
|---|---|---|
| Cursor | Staying in an AI editor; Cloud Agents and Bugbot for background work | Free; Plus $8; Premium $30 a month and up |
| Devin | A teammate you tag in Slack or Teams with its own workspace | Free; Pro $20; Max $200 a month |
| GitHub Copilot cloud agent | Teams that live in GitHub issues and pull requests | Paid plans from $10 a month |
| Jules | Trying an asynchronous cloud agent for free | 15 tasks a day free |
| opencode, Aider, Cline, OpenHands | Open source, any model, local models included | Free; you pay your model provider |
| Reason | An always-on teammate that codes: cloud computer, memory, Loops, Slack, any connected model | Pro $50, Max $200 a month |
Reason's own result is on the earlier Coding Agent Index v1.5: on GPT-6 Astra, Reason 1.1 scored 65.1 against Codex's 62.5 on the same tasks and graders. It's Reason's benchmark of its own harness, reproducible with its published runner, and not comparable with v2.0, so it isn't in the ranked table.
Hit your limit? Reason keeps going on your other connected accounts or Reason credits.
Sources (checked Nov 2, 2026)
- Artificial Analysis: Coding Agent Index
- Artificial Analysis: coding agent methodology (v2.0)
- Artificial Analysis: Claude Code vs Codex
- Artificial Analysis: Claude Code vs Grok Build
- Terminal-Bench 4.0 leaderboard
- Snorkel: Terminal-Bench 4.0 leaderboard mirror
- Cursor: pricing
- Devin: pricing
- GitHub Docs: Copilot plans
- Jules docs: usage limits
- anomalyco/opencode on GitHub (MIT)
- Aider-AI/aider on GitHub (Apache-2.0)
- cline/cline on GitHub (Apache-2.0)
- OpenHands/OpenHands on GitHub (MIT)
- Reason: Reason 1.1 Coding Agent Index results (Oct 10, 2026)
- Reason benchmark repository and methodology
Questions
What is the best coding agent in 2026?
On public benchmarks, Claude Code: on Opus 5.5 it scores 62 on Artificial Analysis's Coding Agent Index v2.0 and 64.8% on Terminal-Bench 4.0, ahead of Codex on GPT-6 Astra (55 and 58.2%).
How should I choose a coding agent?
Start with the plan you already pay for and the model you trust, then run the same few tasks you know the answers to in your top two. Benchmarks narrow the list; your own repository decides.
Which coding agents are free?
opencode, Aider, Cline and OpenHands are free and open source. Codex is included in ChatGPT Free and Go, Jules allows 15 tasks a day, and Cursor and Devin have free tiers.
Why isn't Reason ranked first?
Because its published result is on Coding Agent Index v1.5, not v2.0. On v1.5 with GPT-6 Astra, Reason 1.1 scored 65.1 against Codex's 62.5; ranking it against v2.0 scores wouldn't be fair.
What happens when an agent hits its usage limit?
Claude Code, Codex and Cursor stop or offer paid usage at their plan's limits. Hit your limit? Reason keeps going on your other connected accounts or Reason credits.
Is Reason affiliated with these vendors?
No. Reason is built by Reason Machines and is not affiliated with or endorsed by Anthropic, OpenAI, Anysphere, Cognition, GitHub, Google or xAI. Facts about their products come from their own pages, linked under Sources.