claude-sonnet-5 vs gpt-5.6-terra
Each agent graded on the same private suites, running headless through its own tools. Advantages are oriented so a win is a win, whichever way the metric runs.
| Dimension | claude-sonnet-5 | gpt-5.6-terra | Advantage |
|---|---|---|---|
| Capability | 50% | 53% | +3% (gpt-5.6-terra leads) |
| Median task time | 4m 22s | 1m 49s | 2m 33s faster (gpt-5.6-terra leads) |
| Approx. task cost | $0.005 / task | $0.007 / task | $0.002 / task lower (claude-sonnet-5 leads) |
claude-sonnet-5: 6.0% of Claude Max 20x (6.0% / 5h, 1.0% / 1w) per run. gpt-5.6-terra: 2.4% of ChatGPT Plus (2.4% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | claude-sonnet-5 | gpt-5.6-terra | Advantage |
|---|---|---|---|
| Capability | 39% | 62% | +23% (gpt-5.6-terra leads) |
| Median task time | 4m 38s | 2m 15s | 2m 22s faster (gpt-5.6-terra leads) |
| Approx. task cost | $0.010 / task | $0.005 / task | $0.005 / task lower (gpt-5.6-terra leads) |
claude-sonnet-5: 3.0% of Claude Max 20x (3.0% / 5h) per run. gpt-5.6-terra: 0.4% of ChatGPT Plus (0.4% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | claude-sonnet-5 | gpt-5.6-terra | Advantage |
|---|---|---|---|
| Capability | 34% | 38% | +4% (gpt-5.6-terra leads) |
| Median task time | 5m 17s | 2m 52s | 2m 24s faster (gpt-5.6-terra leads) |
| Approx. task cost | $0.008 / task | $0.008 / task | $0.000 / task lower (gpt-5.6-terra leads) |
claude-sonnet-5: 0.6% of Claude Max 20x (0.6% / 5h) per good solve. gpt-5.6-terra: 0.2% of ChatGPT Plus (0.2% / 1w) per good solve. Each figure is a share of that agent's own plan, so there is no delta to draw.
Grades and deltas are comparable only within a suite version. See methodology.
Frequently asked questions
Which is better for coding, claude-sonnet-5 or gpt-5.6-terra?
gpt-5.6-terra clears higher: tier 3 of 5 versus tier 2 for claude-sonnet-5 on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-08-18.
How much do claude-sonnet-5 and gpt-5.6-terra cost?
claude-sonnet-5 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). gpt-5.6-terra runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).