gpt-5.1 vs gemini-2.5-flash
Side-by-side comparison of gpt-5.1 and gemini-2.5-flash — benchmarks, pricing, context window and capabilities. Both are accessible through Requesty's unified API. gpt-5.1 outperforms gemini-2.5-flash on 9 of 9 shared benchmarks.
gpt-5.1
Input / 1M
$1.25
Output / 1M
$10.00
Context
400K
Model ID
openai/gpt-5.1
gemini-2.5-flash
Input / 1M
$0.30
Output / 1M
$2.50
Context
1.0M
Model ID
google/gemini-2.5-flash
Benchmark comparison
MMLU Proknowledge
gpt-5.189.4%
gemini-2.5-flash78.4%
GPQA Diamondreasoning
gpt-5.183.2%
gemini-2.5-flash68.3%
HumanEvalcoding
gpt-5.194.7%
gemini-2.5-flash88.5%
SWE-Bench Verifiedcoding
gpt-5.176.8%
gemini-2.5-flash53.2%
MATHmath
gpt-5.194.8%
gemini-2.5-flash85.3%
AIME 2024math
gpt-5.190.1%
gemini-2.5-flash72.1%
MMMUmultimodal
gpt-5.180.3%
gemini-2.5-flash72.5%
LiveBenchreasoning
gpt-5.176.2%
gemini-2.5-flash64.2%
τ-bench Retailagentic
gpt-5.173.5%
gemini-2.5-flash61.5%
Scores sourced from official model cards, Artificial Analysis, and public leaderboards. Benchmarks measure specific skills and don't capture every aspect of model quality.
Pricing & specifications
| gpt-5.1 | gemini-2.5-flash | |
|---|---|---|
| Input price / 1M | $1.25 | $0.30 |
| Output price / 1M | $10.00 | $2.50 |
| Context window | 400K tokens | 1.0M tokens |
| Max output | 128K tokens | 66K tokens |
| Vision input | Yes | Yes |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Prompt caching | Yes | Yes |
| Computer use | — | — |
| Provider | OpenAI Inc. | Google LLC (Gemini API) |
Questions people ask
Is gpt-5.1 better than gemini-2.5-flash?
gpt-5.1 outperforms gemini-2.5-flash on 9 of 9 shared benchmarks. See the benchmark comparison above for specifics — gpt-5.1 and gemini-2.5-flash have different strengths across reasoning, coding, math and multimodal tasks.
Which is cheaper — gpt-5.1 or gemini-2.5-flash?
gemini-2.5-flash is cheaper. gpt-5.1 costs $1.25/$10.00 per 1M input/output tokens, while gemini-2.5-flash costs $0.30/$2.50.
Can I use gpt-5.1 and gemini-2.5-flash through the same API?
Yes. Requesty provides a single OpenAI-compatible API that routes to both. Change just the "model" parameter to switch — "openai/gpt-5.1" or "google/gemini-2.5-flash" — no other code changes needed.
What are the context windows?
gpt-5.1 supports up to 400K tokens of context. gemini-2.5-flash supports up to 1.0M tokens. Longer context means you can feed larger documents or codebases in a single prompt, though quality often degrades past 128K for most models.
Switch between gpt-5.1 and gemini-2.5-flash with one line of code
Requesty provides a single OpenAI-compatible API for 400+ models. Change the model parameter, not your code.
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