Head to head / curated pair / cycle 04
Aider vs Cline
Both products were given the identical 9 prompt vibeOps specification, 5 times each. Nothing on this page is an impression, all of it is a measurement from the same harness.
The second fastest median in the whole index and by some distance the cheapest per completed prompt. It works on a small explicit set of files and commits as it goes, which is excellent discipline and also why it scores lower on the prompts that need a change across many files at once. Nothing about it is hosted, so there is no platform risk at all.
An open source agent inside your editor that asks permission before each step, which is slower to drive and much easier to trust. It matched the commercial agents on the correctness prompts and lost time to the approval loop rather than to the model. Cost per full run was among the lowest we recorded because nothing is spent on a platform licence.
Index gap
4.24
Cline leads
Axes won
2 / 7
Aider versus Cline, of ten axes
Faster median
Aider
39.4 s per prompt
Higher pass rate
Cline
80.0%
Every measurement, side by side
Cyan marks the better figure on each row. The delta column is the first product minus the second.
| Measurement | Aider | Cline | Delta |
|---|---|---|---|
| Composite index | 67.27 | 71.51 | -4.24 |
| Agent performance (weight 18) | 72.0 | 82.0 | -10.00 |
| Reliability (weight 18) | 68.9 | 80.0 | -11.10 |
| Scalability (weight 13) | 64.0 | 72.0 | -8.00 |
| SEO and GEO (weight 12) | 54.0 | 57.0 | -3.00 |
| API and MCP (weight 9) | 62.0 | 70.0 | -8.00 |
| Integrations (weight 8) | 58.0 | 72.0 | -14.00 |
| Design output (weight 7) | 52.0 | 63.0 | -11.00 |
| Speed (weight 7) | 79.7 | 33.0 | +46.70 |
| Value (weight 5) | 94.0 | 88.0 | +6.00 |
| Code ownership (weight 3) | 99.0 | 99.0 | +0.00 |
| Median seconds per prompt | 39.4 | 95.1 | -55.70 |
| p10 seconds | 22.5 | 47.4 | -24.90 |
| p90 seconds | 75.7 | 201.7 | -126.00 |
| Executions failed | 7 | 1 | +6.00 |
| HTML bytes, no JS | 17.0 KB | 21.0 KB | -4096.00 |
| LCP milliseconds | 1,920 | 1,860 | +60.00 |
| CLS | 0.050 | 0.040 | +0.01 |
| Entry price EUR | 0.00 | 0.00 | +0.00 |
Screenshot diff
Both landing pages, captured by the lab on 14 Aug 2026 at 1440 by 900. Stored locally, never hotlinked.
Aider, captured 14 Aug 2026.
Cline, captured 14 Aug 2026.
Speed spread on a shared scale
Aider
22.5 / 39.4 / 75.7 seconds
Cline
47.4 / 95.1 / 201.7 seconds
Axis by axis, who wins
Aider wins 2 of 10
- Speed79.7
- Value94.0
Cline wins 7 of 10
- Agent performance82.0
- Reliability80.0
- Scalability72.0
- SEO and GEO57.0
- API and MCP70.0
- Integrations72.0
- Design output63.0
Verdict
Cline takes the composite by 4.24 points. It wins on the weighted total, but the axis table is where the real decision sits: Aider takes 2 axes and Cline takes 7.
If the work in front of you is mostly interface, weight the design and speed rows. If it is a product with an API, webhooks and background jobs, weight agent performance, reliability and the API and MCP row, which together carry 45 of the 100 index points. If the project has to outlive its vendor, read the code ownership row first and treat everything else as secondary.
Both products in this comparison were measured in the same cycle, on the same specification, by the same harness. The per run data for each is on its product page and in /api/runs.json.