AI Models · Compare
GPT-5.5 vs Claude 4 Sonnet
Which AI model is better in 2026? Compare GPT-5.5 and Claude 4 Sonnet on benchmarks, pricing, speed, context window, and real-world fit.
Quick summary
Claude 4 Sonnet is currently the stronger overall pick for coding, context, and price. GPT-5.5 wins on reasoning and math. Claude 4 Sonnet is also cheaper on blended API price ($6.00 vs $7.50 / 1M).
Overall winner
Claude 4 Sonnet
GPT-5.5 wins
- Reasoning
- Math
Claude 4 Sonnet wins
- Coding
- Context
- Price
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Pick any two modelsGPT-5.5 vs Claude 4 Sonnet: overview
GPT-5.5 (OpenAI) and Claude 4 Sonnet (Anthropic) 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. Claude 4 Sonnet: The Anthropic sweet spot — Opus-class coding at a fraction of the price. This GPT-5.5 vs Claude 4 Sonnet 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). Claude 4 Sonnet is proprietary with 500k context at about $6.00 blended / 1M (intelligence 75/100). Those gaps drive most “GPT-5.5 vs Claude 4 Sonnet” searches — quality versus cost, closed versus open, cloud versus self-host.
Where they differ most: GPT-5.5 tends to lead on reasoning and math, while Claude 4 Sonnet leads on coding, context, and price. Choose Claude 4 Sonnet 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. Claude 4 Sonnet fits production coding tools, long-context rag, and tool use. Scroll to pricing, real-world tasks, and the who-should-choose section for decision support.
People search “GPT-5.5 vs Claude 4 Sonnet”, “which is better”, and “GPT-5.5 vs Claude 4 Sonnet 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; Claude 4 Sonnet is a hosted alternative from Anthropic. 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 Claude 4 Sonnet 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 | Claude 4 Sonnet |
|---|---|---|
| Input / 1M tokens | $5.00 | $3.00 |
| Output / 1M tokens | $15.00 | $15.00 |
| Blended (3:1) / 1M | $7.50 | $6.00 |
| Est. cost @ 1M blended tokens | $7.50 | $6.00 |
| Est. cost @ 10M blended tokens | $75.00 | $60.00 |
| Est. cost @ 100M blended tokens | $750.00 | $600.00 |
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, and MATH, indicating stronger reasoning-oriented scores. Claude 4 Sonnet leads on HumanEval. Claude 4 Sonnet 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 Claude 4 Sonnet tends to split common product tasks based on catalog strengths, price, and modalities.
| Task | Winner |
|---|---|
| Coding | Claude 4 Sonnet |
| Blog writing | GPT-5.5 |
| Research | Claude 4 Sonnet |
| Customer support | Claude 4 Sonnet |
| Cheap API / high volume | Claude 4 Sonnet |
| AI agents | Claude 4 Sonnet |
| Summarization | GPT-5.5 |
| Translation | GPT-5.5 |
| Vision / multimodal | GPT-5.5 |
| Self-hosting / open weights | Claude 4 Sonnet |
Technical differences
| Feature | GPT-5.5 | Claude 4 Sonnet |
|---|---|---|
| Provider | OpenAI | Anthropic |
| License | Proprietary | Proprietary |
| Pricing model | tokens | tokens |
| Context window | 400k tokens | 500k tokens |
| Max output | 16k tokens | 16k 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
- Best $/HumanEval ratio
- Fast
- 500k context
- Behind Opus on hardest reasoning
- Production coding tools
- Long-context RAG
- Tool use
Who should choose which
Choose GPT-5.5 if
- You need stronger reasoning, coding, or math quality
- Agentic workflows
- Complex coding
Choose Claude 4 Sonnet if
- You need stronger reasoning, coding, or math quality
- You need a larger context window
- API budget is the top constraint
- Production coding tools
- Long-context RAG
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
Claude 4 Sonnet
Pros
- Best $/HumanEval ratio
- Fast
- 500k context
Cons
- Behind Opus on hardest reasoning
Editorial verdict
Claude 4 Sonnet edges this matchup — with caveats
Claude 4 Sonnet is the better choice when you prioritize coding, context, and price. GPT-5.5 stands out for reasoning and math, making it a strong option when those dimensions matter more than raw leaderboard rank. If maximum measured performance matters, Claude 4 Sonnet 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 Claude 4 Sonnet review, or open the full AI models table.
GPT-5.5 vs Claude 4 Sonnet — frequently asked questions
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