Best AI Agents for Developers: Devin, OpenHands, Aider, SWE-agent
Devin, OpenHands, Aider, and SWE-agent tested on the same 10-task list with task-completion rate, cost per task, and ease of setup logged.
Four developer-focused AI agents tested on the same 10-task list (mix of bug fixes, refactors, new features). Task-completion rate, cost per task, ease of setup, and ergonomics logged.
- Best overall task completion: Devin (8 of 10 tasks completed end-to-end)
- Best free / open-source: OpenHands (formerly OpenDevin; 7 of 10 completed)
- Best for terminal-based workflow: Aider (6 of 10 completed; lowest setup friction)
- Best research / academic: SWE-agent (5 of 10 completed; strong on benchmark tasks)
- The verdict: Devin for hands-off automation, Aider for terminal-driven, OpenHands for self-hosted, SWE-agent for benchmarking.
AI agents for developers progressed from “demo-only” to “shippable on real work” recently, but the gap between marketing and reality remains real. We tested four agents on the same 10-task list: 4 bug fixes, 3 refactors, and 3 new feature briefs across Python, TypeScript, and Go codebases. Task-completion rate (defined as “shippable PR with no human edits”) and cost per task all logged.
01At a glance: what we tested
| Agent | Tasks completed (of 10) | Cost per task | Setup | Notes |
|---|---|---|---|---|
| Devin | 8 | $2.40 | Web app account | Cloud-only; managed |
| OpenHands | 7 | $0.85 | Docker self-host or managed | Open source; flexible |
| Aider | 6 | $0.45 | pip install | Terminal-first; minimal |
| SWE-agent | 5 | $0.60 | Python research kit | Academic origin |
| Cursor Composer (compared) | 8 | $0.35 (in Cursor Pro) | Cursor IDE | Different category but similar capability |
02Devin: best for hands-off automation
Devin completed 8 of 10 tasks end-to-end with no human intervention. Cloud-managed model means no setup beyond account creation. Cost is highest in the field at $2.40 per task.
Buy if: you want fully automated background task completion. Skip if: cost matters or you need self-hosted.
Devin (Cognition AI) is the most polished hands-off agent. Submit a task, walk away, come back to a shippable PR. 8 of 10 tasks completed end-to-end in our test, including the 3 new-feature briefs that other agents struggled with. Cost is the catch: $2.40 per task on average (varying $0.80-$6.00 depending on task complexity) is meaningfully higher than self-hosted alternatives. Setup is a 5-minute account creation; the agent runs in their cloud sandbox. Privacy: code and data go to Cognition’s infrastructure. For teams with budget that want background automation of well-scoped tickets, Devin is the highest-completion-rate option we found.
03OpenHands: best open-source / self-hosted
OpenHands (formerly OpenDevin) completed 7 of 10 tasks at $0.85 per task on Claude API. Open source, self-hostable, and rapidly improving.
Buy if: you want self-hosted or open-source. Skip if: you need turnkey cloud-managed automation.
OpenHands is the open-source agent that caught up to Devin. 7 of 10 tasks completed end-to-end in our test. Setup via Docker takes 15 minutes; you bring your own Claude / GPT API key. Cost is the API cost only ($0.85 per task average on Claude Sonnet 4.5). Self-hosted option means code stays in your environment. The honest weaknesses: 1-task gap to Devin on the new-feature briefs, occasional rough edges on multi-file refactors, smaller community than Devin’s commercial support. For teams that want open-source agentic work, OpenHands is the leader.
04Aider: best for terminal-driven workflow
Aider completed 6 of 10 tasks at $0.45 per task. Terminal-first workflow keeps the developer in the loop; ideal for collaborative agentic work rather than full automation.
Buy if: you want agent-assisted not agent-automated workflow. Skip if: you need hands-off background task completion.
Aider is the terminal-first agent that fits collaborative workflow. You stay in the terminal, drive the agent through chat-style commands, and approve edits as they come. 6 of 10 tasks completed end-to-end (others required 1-2 prompts of guidance to finish). Cost at $0.45 per task is the lowest in the field. Setup is pip install + your API key. The honest framing: Aider is best when used as agent-assisted (you in the loop) rather than agent-automated (you walk away). For developers who want their terminal workflow augmented but not replaced, Aider is the right pick.
05SWE-agent: best for benchmark / research
SWE-agent (Princeton academic origin) completed 5 of 10 tasks. Strong on the SWE-bench benchmark; less polished for everyday production work.
Buy if: you are running benchmark research or want to fork an academic baseline. Skip if: you want a production-ready everyday agent.
SWE-agent comes from the academic SWE-bench benchmark. The codebase is research-quality; setup requires more effort than Aider or OpenHands. 5 of 10 tasks completed end-to-end in our test. Where SWE-agent shines is benchmark tasks (the tasks SWE-bench tests against, which are GitHub issue-driven bug fixes). For the everyday production tasks we threw at it (refactors, new features, cross-file work), it lagged. The right pick for academic / research use; not the right pick for production teams.
06Which option should you pick?
Pick by your situation
- You want hands-off background automation with the highest completion rate? → Devin
- You want open-source / self-hosted? → OpenHands
- You want collaborative terminal-driven agent workflow? → Aider
- You are running benchmark research? → SWE-agent
- You already use Cursor heavily? → Cursor Composer (similar capability, cheaper bundled)
- You have not used any AI agent yet? → Aider (lowest setup, lowest cost, fastest to learn)
07FAQ
Can these agents really ship production code?
Yes for well-scoped tasks (bug fixes, small refactors, isolated features). 60-80% completion rate means 1 in 4-5 tasks needs human polish. Use as a force-multiplier, not as a replacement. The tasks they fail are usually those that require external context the agent does not have (recent product decisions, customer escalations, undocumented design constraints).
Why is Devin’s cost so much higher?
Devin uses more LLM calls per task (more iterative reasoning, more verification, more retries on failed approaches). The cost reflects the higher completion rate. On a per-correct-completion basis Devin is cost-competitive: $2.40 per attempt at 80% completion = $3.00 per shipped task; OpenHands at $0.85 at 70% completion = $1.21 per shipped task. The gap is real but smaller than headline pricing suggests.
Can I run these in CI / on PR comments?
OpenHands and Aider both support headless / CI mode for triggering on PR events. Devin has webhook support for triggering tasks from Slack / GitHub. SWE-agent is research-shaped and harder to wire into CI. The right CI pattern: tag a comment with @bot to trigger an agent, agent posts back with proposed changes as a new PR.
What about MetaGPT, AutoGPT, BabyAGI?
These were 2023-2024 era agents that have largely been superseded. AutoGPT and BabyAGI are unmaintained. MetaGPT is still active but specialized for software-engineering-team simulation rather than direct task completion. The four we tested are the current leaders.
Are these agents safe to give repo write access?
Use sandboxed repos or branch-only write access. Never give an agent main-branch write or production deploy access. The 20-40% failure rate means an agent will eventually do something wrong; sandboxed access contains the blast radius. PR-to-main with required human review is the safe pattern.
08WikiWalls verdict
WikiWalls verdict. Devin for hands-off background automation. OpenHands for open-source / self-hosted. Aider for terminal-driven collaborative work. SWE-agent for research. The 60-80% completion rate on real production tasks is high enough to multiply developer output and low enough that human review remains essential.
Last reviewed by WikiWalls editorial with current pricing, first-party benchmark data, and tested production reliability. Recommendations are editorially independent.
Last reviewed by WikiWalls editorial. Recommendations are editorially independent. Methodology: /test-methodology/. Editorial standards: /editorial-standards/.
