Compare / head-to-head
Gemini 2.5 FlashvsGemini 3.5 Flash
Gemini 3.5 Flash leads 1 of 1 shared benchmark. Gemini 2.5 Flash is 3.8x cheaper per token. Both offer a 1.0M-token context window.
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0 – 1
Gemini 3.5 Flash leads
Cheaper per token
Gemini 2.5 Flash
3.8x cheaper, input + output
Larger context
Tie
both 1.0M tokens
Provider uptime (30d)
100%
Google
Gemini 2.5 Flash
Google · released 2025-06-17
textvisionaudio
Gemini 3.5 Flash
Google · released 2026-05-19
textvisionaudio
Quality
Benchmark matrix
1 shared · 7 only Gemini 2.5 Flash · 14 only Gemini 3.5 Flash| Benchmark | Gemini 2.5 Flash | Gemini 3.5 Flash | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 1 | ||||
| GPQA Diamond | 82.8% ↗ | 92.8% ↗epoch | -10 pt | Gemini 3.5 Flash |
| Only Gemini 2.5 Flash reports · 7 | ||||
| SWE-bench Verified | 48.9% ↗ | not reported | — | — |
| AIME 2025 | 72% ↗ | not reported | — | — |
| Humanity's Last Exam (no tools) | 11% ↗ | not reported | — | — |
| LMArena Elo | 1417.3 ↗ | not reported | — | — |
| Aider Polyglot | 56.7% ↗ | not reported | — | — |
| LiveCodeBench | 59.3% ↗ | not reported | — | — |
| MMMU | 79.7% ↗ | not reported | — | — |
| Only Gemini 3.5 Flash reports · 14 | ||||
| AIME 2026 | not reported | 95% ↗matharena ⚠ | — | — |
| ARC-AGI-2 | not reported | 72.1% ↗ | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | not reported | 26.8% ↗epoch | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | not reported | 62.8% ↗epoch | — | — |
| GDPVal-AA | not reported | 1656 ↗ | — | — |
| Humanity's Last Exam (full set, text + MM) | not reported | 40.2% ↗ | — | — |
| MCP Atlas | not reported | 83.6% ↗ | — | — |
| MMMU-Pro | not reported | 83.6% ↗ | — | — |
| OSWorld-Verified | not reported | 78.4% ↗ | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | not reported | 95.6% ↗epoch | — | — |
| SimpleQA Verified | not reported | 66.2% ↗epoch | — | — |
| SWE-Bench Pro (Public) | not reported | 55.1% ↗ | — | — |
| SWE-bench Verified (Epoch AI run) | not reported | 79.3% ↗epoch | — | — |
| Terminal-bench 2.1 | not reported | 76.2% ↗ | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Gemini 2.5 Flash minus Gemini 3.5 Flash in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | Gemini 2.5 Flash | Gemini 3.5 Flash | Edge |
|---|---|---|---|
| Context window | 1.0M tokens | 1.0M tokens | Tie |
| Max output | 66K tokens | 66K tokens | Tie |
| Input price / 1M | $0.3 ↗ | $1.5 ↗ | Gemini 2.5 Flash |
| Output price / 1M | $2.5 ↗ | $9 ↗ | Gemini 2.5 Flash |
| Cached input / 1M | $0.03 ↗ | $0.15 ↗ | Gemini 2.5 Flash |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $2.8 | $10.5 | Gemini 2.5 Flash |
| Modalities | text · vision · audio | text · vision · audio | Tie |
| Released | 2025-06-17 | 2026-05-19 | — |
| Cited benchmark scores | 9 | 15 | — |
Reliability
Google status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Gemini 2.5 Flash vs …
Models sharing the most benchmarksMore matchups
Gemini 3.5 Flash vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Gemini 2.5 Flash and Gemini 3.5 Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.