Head to head
GPT-5 vs o3
GPT-5 is legacy; o3 is legacy.
For tasks, about a month.
Verdict · stale basis
GPT-5 costs $0.74 per solved task against
o3 at $0.89 — ▼ 1.2x cheaper.
Over 200 tasks that is $29 a month.
On output token price alone o3 looks 1.3x cheaper. The ranking reverses once you divide by pass rate — the cheaper tokens do not win the task.
Verified pricing, pass rate and cost per solved task for GPT-5 and o3| Figure | GPT-5 | o3 |
|---|
| Input $/Mtok | $1.25 | $2 |
|---|
| Output $/Mtok | $10 | $8 |
|---|
| Cached input $/Mtok | $0.125 | $0.5 |
|---|
| Pass rate | 88% | 81% |
|---|
| Cost per solved task | $0.74stale | $0.89stale |
|---|
| Cost per month | $148 | $177 |
|---|
Cost per month against tasks per month · drag the marker
Solid measured · dashed modelled · dotted stale. The gap is the verdict.
Source: Aider polyglot benchmark · verified 2026-08-21 · prices from each provider's pricing page; measured rows ignore the tier · Methodology · All models at these settings