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GPT-5.5 vs GPT-4o
Which AI model is better in 2026? Compare GPT-5.5 and GPT-4o on benchmarks, pricing, speed, context window, and real-world fit.
Quick summary
GPT-5.5 is currently the stronger overall pick for reasoning, coding, math, and context. GPT-4o wins on speed and price. GPT-4o remains the budget pick at $4.38 vs $7.50 blended / 1M tokens.
Overall winner
GPT-5.5
GPT-5.5 wins
- Reasoning
- Coding
- Math
- Context
GPT-4o wins
- Speed
- Price
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Pick any two modelsGPT-5.5 vs GPT-4o: overview
GPT-5.5 (OpenAI) and GPT-4o (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. GPT-4o: OpenAI’s vision-and-voice flagship from 2024 — still a great default. This GPT-5.5 vs GPT-4o 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). GPT-4o is proprietary with 128k context at about $4.38 blended / 1M (intelligence 72/100). Those gaps drive most “GPT-5.5 vs GPT-4o” searches — quality versus cost, closed versus open, cloud versus self-host.
Where they differ most: GPT-5.5 tends to lead on reasoning, coding, math, and context, while GPT-4o leads on speed and price. 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. GPT-4o fits general-purpose chat, voice apps, and vision tasks. Scroll to pricing, real-world tasks, and the who-should-choose section for decision support.
People search “GPT-5.5 vs GPT-4o”, “which is better”, and “GPT-5.5 vs GPT-4o 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; GPT-4o 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 GPT-4o 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 | GPT-4o |
|---|---|---|
| Input / 1M tokens | $5.00 | $2.50 |
| Output / 1M tokens | $15.00 | $10.00 |
| Blended (3:1) / 1M | $7.50 | $4.38 |
| Est. cost @ 1M blended tokens | $7.50 | $4.38 |
| Est. cost @ 10M blended tokens | $75.00 | $43.80 |
| Est. cost @ 100M blended tokens | $750.00 | $438.00 |
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, MMLU Pro, GPQA, MATH, and HumanEval, indicating stronger coding and reasoning-oriented scores. GPT-4o 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 GPT-4o 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-4o |
| Cheap API / high volume | GPT-4o |
| AI agents | GPT-5.5 |
| Summarization | GPT-5.5 |
| Translation | GPT-5.5 |
| Vision / multimodal | GPT-5.5 |
| Self-hosting / open weights | GPT-4o |
Technical differences
| Feature | GPT-5.5 | GPT-4o |
|---|---|---|
| Provider | OpenAI | OpenAI |
| License | Proprietary | Proprietary |
| Pricing model | tokens | tokens |
| Context window | 400k tokens | 128k tokens |
| Max output | 16k tokens | 16k tokens |
| Vision input | Yes | Yes |
| Audio input | No | Yes |
| Text output | Yes | Yes |
| Image output | No | No |
| Video output | No | No |
| Audio output | No | Yes |
| 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
- Strong multimodal
- Voice-native
- Mature ecosystem
- Weaker than GPT-5.5 on reasoning
- Smaller context vs newer models
- General-purpose chat
- Voice apps
- Vision tasks
Who should choose which
Choose GPT-5.5 if
- You need stronger reasoning, coding, or math quality
- You need a larger context window
- Agentic workflows
- Complex coding
Choose GPT-4o if
- You care about faster token throughput
- API budget is the top constraint
- General-purpose chat
- Voice apps
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
GPT-4o
Pros
- Strong multimodal
- Voice-native
- Mature ecosystem
Cons
- Weaker than GPT-5.5 on reasoning
- Smaller context vs newer models
Editorial verdict
GPT-5.5 edges this matchup — with caveats
GPT-5.5 is the better choice when you prioritize reasoning, coding, math, and context. GPT-4o stands out for speed and price, 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 cost and control matter more, GPT-4o 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 GPT-4o review, or open the full AI models table.
GPT-5.5 vs GPT-4o — frequently asked questions
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