AI Models · Compare
GPT-5.5 vs Gemini 2.5 Pro
Which AI model is better in 2026? Compare GPT-5.5 and Gemini 2.5 Pro on benchmarks, pricing, speed, context window, and real-world fit.
Quick summary
Gemini 2.5 Pro is currently the stronger overall pick for math, context, speed, and price. GPT-5.5 wins on reasoning and coding. Gemini 2.5 Pro is also cheaper on blended API price ($2.19 vs $7.50 / 1M).
Overall winner
Gemini 2.5 Pro
GPT-5.5 wins
- Reasoning
- Coding
Gemini 2.5 Pro wins
- Math
- Context
- Speed
- Price
Want to compare different models?
Pick any two modelsGPT-5.5 vs Gemini 2.5 Pro: overview
GPT-5.5 (OpenAI) and Gemini 2.5 Pro (Google) are frequently compared by teams choosing an AI stack in 2026. GPT-5.5: OpenAI’s 2026 flagship — strongest at reasoning, coding and tool use. Gemini 2.5 Pro: 2M-token context + native multimodality — unbeatable for huge docs. This GPT-5.5 vs Gemini 2.5 Pro comparison covers benchmarks, pricing, context window, speed, modalities, strengths, weaknesses, and who should pick which model.
GPT-5.5 is proprietary with a 400k-token context window and a blended API price near $7.50 / 1M tokens (intelligence index 82/100). Gemini 2.5 Pro is proprietary with 2M context at about $2.19 blended / 1M (intelligence 78/100). Those gaps drive most “GPT-5.5 vs Gemini 2.5 Pro” searches — quality versus cost, closed versus open, cloud versus self-host.
Where they differ most: GPT-5.5 tends to lead on reasoning and coding, while Gemini 2.5 Pro leads on math, context, speed, and price. Choose Gemini 2.5 Pro when you want the stronger overall profile on our scorecard; validate with your own evals before migrating production traffic.
GPT-5.5 is often shortlisted for agentic workflows, complex coding, and hard math & research. Gemini 2.5 Pro fits whole-codebase analysis, long-doc workflows, and video qa. Scroll to pricing, real-world tasks, and the who-should-choose section for decision support.
People search “GPT-5.5 vs Gemini 2.5 Pro”, “which is better”, and “GPT-5.5 vs Gemini 2.5 Pro pricing” for the same reason: switching models is expensive if quality drops, and staying put is expensive if you overpay. Use the winner card for a fast answer, the head-to-head table for receipts, and the editorial verdict for a human recommendation. GPT-5.5 currently ranks among frontier options from OpenAI; Gemini 2.5 Pro is a hosted alternative from Google. If API pricing is your main concern, start with the pricing section; for multimodal workloads, check vision/audio rows in technical differences; for agents and long documents, prioritize context and reasoning wins.
Head to head
Pricing comparison
API cost is often the deciding factor in GPT-5.5 vs Gemini 2.5 Pro for high-volume apps. Figures below use catalog list prices with a 3:1 input:output blend for monthly estimates. Cached input, batch, and realtime surcharges vary by provider — confirm on official docs.
| API cost | GPT-5.5 | Gemini 2.5 Pro |
|---|---|---|
| Input / 1M tokens | $5.00 | $1.25 |
| Output / 1M tokens | $15.00 | $5.00 |
| Blended (3:1) / 1M | $7.50 | $2.19 |
| Est. cost @ 1M blended tokens | $7.50 | $2.19 |
| Est. cost @ 10M blended tokens | $75.00 | $21.90 |
| Est. cost @ 100M blended tokens | $750.00 | $219.00 |
Cached input, batch API, and realtime surcharges are provider-specific and not always published in our catalog — verify on official pricing pages.
Benchmark showdown
GPT-5.5 leads on MMLU and HumanEval, indicating stronger coding and reasoning-oriented scores. Gemini 2.5 Pro leads on MMLU Pro, GPQA, and MATH. Gemini 2.5 Pro remains attractive for production deployments on price. Raw benchmarks shortlist models — run task-specific evals before you switch.
Real-world performance
Beyond academic scores, here is how GPT-5.5 vs Gemini 2.5 Pro tends to split common product tasks based on catalog strengths, price, and modalities.
| Task | Winner |
|---|---|
| Coding | GPT-5.5 |
| Blog writing | GPT-5.5 |
| Research | Gemini 2.5 Pro |
| Customer support | Gemini 2.5 Pro |
| Cheap API / high volume | Gemini 2.5 Pro |
| AI agents | Gemini 2.5 Pro |
| Summarization | GPT-5.5 |
| Translation | GPT-5.5 |
| Vision / multimodal | GPT-5.5 |
| Self-hosting / open weights | Gemini 2.5 Pro |
Technical differences
| Feature | GPT-5.5 | Gemini 2.5 Pro |
|---|---|---|
| Provider | OpenAI | |
| License | Proprietary | Proprietary |
| Pricing model | tokens | tokens |
| Context window | 400k tokens | 2M tokens |
| Max output | 16k tokens | 66k tokens |
| Vision input | Yes | Yes |
| Audio input | No | Yes |
| Text output | Yes | Yes |
| Image output | No | No |
| Video output | No | No |
| Audio output | No | No |
| Self-host friendly | No | No |
| Docs | Available | Available |
Strengths, weaknesses and best-for
- Best-in-class reasoning
- Huge 400k context
- Strong tool use and agents
- Expensive vs Sonnet for non-reasoning tasks
- Higher latency than gpt-5.5-mini
- Agentic workflows
- Complex coding
- Hard math & research
- 2M context
- Native video understanding
- Strong on math
- Output ceiling lower than competitors
- Whole-codebase analysis
- Long-doc workflows
- Video QA
Who should choose which
Choose GPT-5.5 if
- You need stronger reasoning, coding, or math quality
- Agentic workflows
- Complex coding
Choose Gemini 2.5 Pro if
- You need stronger reasoning, coding, or math quality
- You need a larger context window
- You care about faster token throughput
- API budget is the top constraint
- Whole-codebase analysis
Pros & cons
GPT-5.5
Pros
- Best-in-class reasoning
- Huge 400k context
- Strong tool use and agents
Cons
- Expensive vs Sonnet for non-reasoning tasks
- Higher latency than gpt-5.5-mini
Gemini 2.5 Pro
Pros
- 2M context
- Native video understanding
- Strong on math
Cons
- Output ceiling lower than competitors
Editorial verdict
Gemini 2.5 Pro edges this matchup — with caveats
Gemini 2.5 Pro is the better choice when you prioritize math, context, speed, and price. GPT-5.5 stands out for reasoning and coding, making it a strong option when those dimensions matter more than raw leaderboard rank. If maximum measured performance matters, Gemini 2.5 Pro wins this matchup. If your niche constraints matter more, GPT-5.5 is difficult to beat. Always confirm with a bake-off on your real prompts before cutting over.
Still deciding? Read the full GPT-5.5 review and Gemini 2.5 Pro review, or open the full AI models table.
GPT-5.5 vs Gemini 2.5 Pro — frequently asked questions
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