Head to head
o3 vs Gemini 2.5 Pro
o3: legacyGemini 2.5 Pro: legacyheavy tier
Verdict · modelled basis
Gemini 2.5 Pro costs 1.1x less per solved task.
On output token price alone, o3 looks 1.3x cheaper (1.6x on input). The ranking reverses once you divide by pass rate — the cheaper tokens do not win the task.
Source: Aider polyglot benchmark · verified 2026-08-21 · prices from each provider's pricing page
Input $/M tokens
lower is better
Output $/M tokens
lower is better
Cost per solved task
modelled basis · lower is better
| o3 | Gemini 2.5 Pro | |
|---|---|---|
| Input $/Mtok | $2 | $1.25 |
| Output $/Mtok | $8 | $10 |
| Cached input $/Mtok | $0.5 | $0.125 |
| Pass rate | 81% | 83% |
| Pass rate source | Aider | Aider |
| Cost basis | modelled | modelled |
| Cost per solved task | $1.99 | $1.76 |
verified 2026-08-21 · heavy task tier; measured rows ignore the tier· Methodology· o3· Gemini 2.5 Pro