High-volume, cost-sensitive work
Choose Gemini Omni Flash
Gemini Omni Flash costs 2% less on a typical mix of three input tokens for every output token ($3.38 against $3.44 per million tokens).
Gemini Omni Flash vs GPT-5.1: price, context and capabilities
Choose Gemini Omni Flash for high-volume, cost-sensitive work, writing and code generation, very long inputs and the latest release; on the other points the two are level or the data is missing.
In short
- Gemini Omni Flash is 2% cheaper than GPT-5.1 at the headline price ($3.38 / 1M tokens vs $3.44 / 1M tokens).
- Gemini Omni Flash reads more per request: 1.05M tokens against 400k.
- Gemini Omni Flash is the newer model (August 2026, against Nov 13, 2025).
- Only Gemini Omni Flash offers audio input, video input.
- Only GPT-5.1 offers prompt caching.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose Gemini Omni Flash
Gemini Omni Flash charges $9.00 per million output tokens, against $10.00 for GPT-5.1. Output dominates the bill when answers are long.
Very long inputs
Choose Gemini Omni Flash
Gemini Omni Flash reads up to 1.05M tokens per request, against 400k for GPT-5.1.
Latest release
Choose Gemini Omni Flash
Gemini Omni Flash is the newer release (August 2026, against Nov 13, 2025 for GPT-5.1).
Monthly cost at three volumes
| Volume | Gemini Omni Flash | GPT-5.1 | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $3.75 | $3.75 | = |
| Production: 20M input, 5M output tokens | $75.00 | $75.00 | = |
| Scale: 500M input, 100M output tokens | $1,650 | $1,625 | GPT-5.1, $25.00 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Gemini Omni Flash | GPT-5.1 | |
|---|---|---|
| Provider | OpenAI | |
| Category | Language models | Language models |
| Status | Generally available | Deprecated |
| Headline price | $3.38 / 1M tokens | $3.44 / 1M tokens |
| Input | $1.50 / 1M tokens | $1.25 / 1M tokens |
| Output | $9.00 / 1M tokens | $10.00 / 1M tokens |
| Cached input | No data | $0.125 / 1M tokens |
| Context window | 1.05M | 400k |
| Max output | No data | 128k |
| Released | August 2026 | Nov 13, 2025 |
| Knowledge cutoff | No data | September 2024 |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Audio input, Video input, Reasoning, Tool calling, Structured output, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API |
| API model id | gemini-omni-1.1-flash | gpt-5.1 |
Benchmarks side by side
Leader in bold.
| Benchmark | Gemini Omni Flash | GPT-5.1 |
|---|---|---|
| Terminal-Bench Hard | No data | 45.5% |
| GPQA Diamond | No data | 87.3% |
| Humanity's Last Exam | No data | 28.5% |
| IFBench (instruction following) | No data | 72.9% |
| τ²-Bench (agentic tool use) | No data | 81.9% |
| MMMU-Pro (visual reasoning) | No data | 75.5% |
| Long-context reasoning (AA-LCR) | No data | 80% |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose Gemini Omni Flash or GPT-5.1?
Choose Gemini Omni Flash for high-volume, cost-sensitive work, writing and code generation, very long inputs and the latest release; on the other points the two are level or the data is missing.
Which is cheaper, Gemini Omni Flash or GPT-5.1?
Gemini Omni Flash is 2% cheaper than GPT-5.1 at the headline price ($3.38 / 1M tokens vs $3.44 / 1M tokens).
Which has the larger context window, Gemini Omni Flash or GPT-5.1?
Gemini Omni Flash reads more per request: 1.05M tokens against 400k.
What is the difference between Gemini Omni Flash and GPT-5.1?
Gemini Omni Flash is made by Google and GPT-5.1 by OpenAI. Gemini Omni Flash is 2% cheaper than GPT-5.1 at the headline price ($3.38 / 1M tokens vs $3.44 / 1M tokens). Gemini Omni Flash reads more per request: 1.05M tokens against 400k. Gemini Omni Flash is the newer model (August 2026, against Nov 13, 2025). Only Gemini Omni Flash offers audio input, video input. Only GPT-5.1 offers prompt caching.
How much do Gemini Omni Flash and GPT-5.1 cost per month?
At 20 million input and 5 million output tokens a month, Gemini Omni Flash costs $75.00 and GPT-5.1 costs $75.00, at standard rates.
Which is newer, Gemini Omni Flash or GPT-5.1?
Gemini Omni Flash was released on August 2026 and GPT-5.1 on Nov 13, 2025.