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GPT-5.5 vs OpenAI o1
Which AI model is better in 2026? Compare GPT-5.5 and OpenAI o1 on benchmarks, pricing, speed, context window, and real-world fit.
Quick summary
GPT-5.5 is currently the stronger overall pick for reasoning, coding, context, speed, and price. OpenAI o1 wins on math. GPT-5.5 is also cheaper on blended API price ($7.50 vs $26.25 / 1M).
Overall winner
GPT-5.5
GPT-5.5 wins
- Reasoning
- Coding
- Context
- Speed
- Price
OpenAI o1 wins
- Math
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Pick any two modelsGPT-5.5 vs OpenAI o1: overview
GPT-5.5 (OpenAI) and OpenAI o1 (OpenAI) 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. OpenAI o1: Long chain-of-thought reasoning — unbeatable on hard math and code. This GPT-5.5 vs OpenAI o1 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). OpenAI o1 is proprietary with 200k context at about $26.25 blended / 1M (intelligence 76/100). Those gaps drive most “GPT-5.5 vs OpenAI o1” searches — quality versus cost, closed versus open, cloud versus self-host.
Where they differ most: GPT-5.5 tends to lead on reasoning, coding, context, speed, and price, while OpenAI o1 leads on math. Choose GPT-5.5 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. OpenAI o1 fits research problems, olympiad-level math, and algorithm design. Scroll to pricing, real-world tasks, and the who-should-choose section for decision support.
People search “GPT-5.5 vs OpenAI o1”, “which is better”, and “GPT-5.5 vs OpenAI o1 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; OpenAI o1 is a hosted alternative from OpenAI. 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 OpenAI o1 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 | OpenAI o1 |
|---|---|---|
| Input / 1M tokens | $5.00 | $15.00 |
| Output / 1M tokens | $15.00 | $60.00 |
| Blended (3:1) / 1M | $7.50 | $26.25 |
| Est. cost @ 1M blended tokens | $7.50 | $26.25 |
| Est. cost @ 10M blended tokens | $75.00 | $262.50 |
| Est. cost @ 100M blended tokens | $750.00 | $2625.00 |
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 HumanEval, indicating stronger coding and reasoning-oriented scores. OpenAI o1 leads on MMLU, MMLU Pro, GPQA, and MATH. GPT-5.5 also undercuts on blended API 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 OpenAI o1 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 | GPT-5.5 |
| Customer support | GPT-5.5 |
| Cheap API / high volume | GPT-5.5 |
| AI agents | GPT-5.5 |
| Summarization | GPT-5.5 |
| Translation | GPT-5.5 |
| Vision / multimodal | GPT-5.5 |
| Self-hosting / open weights | GPT-5.5 |
Technical differences
| Feature | GPT-5.5 | OpenAI o1 |
|---|---|---|
| Provider | OpenAI | OpenAI |
| License | Proprietary | Proprietary |
| Pricing model | tokens | tokens |
| Context window | 400k tokens | 200k tokens |
| Max output | 16k tokens | 100k tokens |
| Vision input | Yes | Yes |
| Audio input | No | No |
| 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
- Tops MATH and GPQA leaderboards
- Self-checks its work
- Very slow
- Very expensive
- Overkill for simple tasks
- Research problems
- Olympiad-level math
- Algorithm design
Who should choose which
Choose GPT-5.5 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
- Agentic workflows
Choose OpenAI o1 if
- You need stronger reasoning, coding, or math quality
- Research problems
- Olympiad-level math
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
OpenAI o1
Pros
- Tops MATH and GPQA leaderboards
- Self-checks its work
Cons
- Very slow
- Very expensive
- Overkill for simple tasks
Editorial verdict
GPT-5.5 edges this matchup — with caveats
GPT-5.5 is the better choice when you prioritize reasoning, coding, context, speed, and price. OpenAI o1 stands out for math, making it a strong option when those dimensions matter more than raw leaderboard rank. If maximum measured performance matters, GPT-5.5 wins this matchup. If your niche constraints matter more, OpenAI o1 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 OpenAI o1 review, or open the full AI models table.
GPT-5.5 vs OpenAI o1 — frequently asked questions
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