Gemini 2.5 Flash vs GPT-5
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
Gemini 2.5 Flash specs · GPT-5 specs- PriceGemini 2.5 Flash
Gemini 2.5 Flash is roughly 33.3× cheaper on output tokens ($0.30 vs $10.00 per 1M).
- Context windowGemini 2.5 Flash
Gemini 2.5 Flash accepts 1.0M tokens vs 400K, 2.6× the room for long documents and codebases.
- BenchmarksTie
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.
- ModalitiesTie
Both handle text, vision, audio.
- OpennessTie
Both are closed-weight, API-only.
On balance Gemini 2.5 Flash edges ahead, winning 2 of 5 categories against GPT-5's 0. Gemini 2.5 Flash is roughly 33.3× cheaper on output tokens ($0.30 vs $10.00 per 1M). Gemini 2.5 Flash accepts 1.0M tokens vs 400K, 2.6× the room for long documents and codebases.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. Both target the same set of modalities (text, vision, audio), so the deciding factors are price, context, and raw quality. Both are closed-weight, API-only.
GPT-5 is the newer of the two, released 4 months after Gemini 2.5 Flash, which usually means a more recent knowledge cutoff and updated safety post-training. Gemini 2.5 Flash is usually picked for rag and long context workloads, while GPT-5 sees more deployments in coding llm and agents. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.
Side-by-side specs
| Spec | Gemini 2.5 Flash | GPT-5 |
|---|---|---|
| Provider | OpenAI | |
| Released | Apr 2025 | Aug 2025 |
| Modalities | text, vision, audio | text, vision, audio |
| Context window | 1.0M tokens | 400K tokens |
| Max output | , | 128K tokens |
| Input · 1M | $0.075 / 1M tokens | $1.25 / 1M tokens |
| Output · 1M | $0.30 / 1M tokens | $10.00 / 1M tokens |
| Knowledge cutoff | 2025-01 | 2024-09 |
| Open weights | No | No |
| API available | Yes | Yes |
Pricing at scale
What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.
- Light usage, 100k in / 50k out per day$0.675 vs $18.75
- Heavy usage, 1M in / 500k out per day$6.75 vs $188
- RAG workload, 5M in / 200k out per day$13.05 vs $248
Light usage, 100k in / 50k out per day: $0.675 vs $18.75 per month, model A comes out ahead. Heavy usage, 1M in / 500k out per day: $6.75 vs $188 per month, model A comes out ahead. RAG workload, 5M in / 200k out per day: $13.05 vs $248 per month, model A comes out ahead.
Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.
- Gemini 2.5 Flash$0.022
- GPT-5$0.625
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
- MMLU,91.4
- HumanEval,96.2
- GPQA,89.4
- SWE-bench Verified,74.9
Gemini 2.5 Flash fits when…
- Cheap and fast
- Long context
- Solid vision
- Cost-sensitive workloads, 33.3× cheaper than GPT-5 on output tokens.
- Long-context tasks, handles 1.0M tokens vs 400K for GPT-5.
GPT-5 fits when…
- Unified model, reasoning routed automatically per query
- Excellent tool-use and JSON-mode discipline
- Strong agent performance on SWE-bench Verified
Consider Gemini 3 Pro
Google's late-2025 flagship, set new benchmarks on long-context, vision, and reasoning at competitive pricing.
Frequently asked
Is Gemini 2.5 Flash or GPT-5 cheaper?
Gemini 2.5 Flash is cheaper at $0.30 / 1M tokens per million output tokens, vs $10.00 / 1M tokens for GPT-5.Which has the larger context window?
Gemini 2.5 Flash accepts 1.0M tokens vs 400K for GPT-5.Is Gemini 2.5 Flash or GPT-5 better for coding?
Both Gemini 2.5 Flash and GPT-5 are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.Are either of these models open source?
Neither model ships open weights, both are accessible only via their respective providers' APIs.When were Gemini 2.5 Flash and GPT-5 released?
Gemini 2.5 Flash was released by Google on 2025-04-09. GPT-5 was released by OpenAI on 2025-08-07.
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