AI Models · Compare

GPT-5.5 vs Claude 4 Opus

Which AI model is better in 2026? Compare GPT-5.5 and Claude 4 Opus on benchmarks, pricing, speed, context window, and real-world fit.

Quick summary

GPT-5.5 is currently the stronger overall pick for reasoning, math, speed, and price. Claude 4 Opus wins on coding and context. GPT-5.5 is also cheaper on blended API price ($7.50 vs $16.00 / 1M).

Overall winner

GPT-5.5

View GPT-5.5 review

GPT-5.5 wins

  • Reasoning
  • Math
  • Speed
  • Price

Claude 4 Opus wins

  • Coding
  • Context

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OpenAI

GPT-5.5

ProprietaryMar 2026

OpenAI’s 2026 flagship — strongest at reasoning, coding and tool use.

Open docs
Anthropic

Claude 4 Opus

ProprietaryFeb 2026

Anthropic’s 2026 flagship — best-in-class on code and long-horizon agents.

Open docs

GPT-5.5 vs Claude 4 Opus: overview

GPT-5.5 (OpenAI) and Claude 4 Opus (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 Opus: Anthropic’s 2026 flagship — best-in-class on code and long-horizon agents. This GPT-5.5 vs Claude 4 Opus 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 Opus is proprietary with 500k context at about $16.00 blended / 1M (intelligence 81/100). Those gaps drive most “GPT-5.5 vs Claude 4 Opus” searches — quality versus cost, closed versus open, cloud versus self-host.

Where they differ most: GPT-5.5 tends to lead on reasoning, math, speed, and price, while Claude 4 Opus leads on coding and context. 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. Claude 4 Opus fits long-context coding, tool-using agents, and document understanding. Scroll to pricing, real-world tasks, and the who-should-choose section for decision support.

People search “GPT-5.5 vs Claude 4 Opus”, “which is better”, and “GPT-5.5 vs Claude 4 Opus 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 Opus 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

Spec
GPT-5.5
Claude 4 Opus
Winner
Reason
Intelligence index↑ better
Winner82
81
GPT-5.5
GPT-5.5 leads on the composite intelligence index (82 vs 81).
Speed↑ better
Winner95 tok/s
50 tok/s
GPT-5.5
GPT-5.5 generates tokens faster (95 vs 50 tok/s).
Time to first token↓ better
Winner0.42 s
1.4 s
GPT-5.5
GPT-5.5 starts streaming sooner (0.42s vs 1.4s TTFT).
Context window↑ better
400k
Winner500k
Claude 4 Opus
Claude 4 Opus wins with 500k tokens — about 1.3× GPT-5.5.
Max output↑ better
16k
Winner32k
Claude 4 Opus
Claude 4 Opus wins this row (32000 vs 16000).
Input price↓ better
Winner$5.00 / 1M tokens
$8.00 / 1M tokens
GPT-5.5
GPT-5.5 is cheaper (~1.6× lower on this price row).
Output price↓ better
Winner$15.00 / 1M tokens
$40.00 / 1M tokens
GPT-5.5
GPT-5.5 is cheaper (~2.7× lower on this price row).
Blended price↓ better
Winner$7.50 / 1M tokens
$16.00 / 1M tokens
GPT-5.5
GPT-5.5 is cheaper (~2.1× lower on this price row).
License
Proprietary
Proprietary
Qualitative / categorical row
Input modalities
text, image
text, image
Qualitative / categorical row
Output modalities
text
text
Qualitative / categorical row

Pricing comparison

API cost is often the deciding factor in GPT-5.5 vs Claude 4 Opus 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 costGPT-5.5Claude 4 Opus
Input / 1M tokens$5.00$8.00
Output / 1M tokens$15.00$40.00
Blended (3:1) / 1M$7.50$16.00
Est. cost @ 1M blended tokens$7.50$16.00
Est. cost @ 10M blended tokens$75.00$160.00
Est. cost @ 100M blended tokens$750.00$1600.00

Cached input, batch API, and realtime surcharges are provider-specific and not always published in our catalog — verify on official pricing pages.

Benchmark showdown

MMLU
GPT-5.5
90.2
Claude 4 Opus
90.0
MMLU Pro
GPT-5.5
78.0
Claude 4 Opus
79.5
GPQA
GPT-5.5
62.5
Claude 4 Opus
65.0
MATH
GPT-5.5
89.1
Claude 4 Opus
88.0
HumanEval
GPT-5.5
93.0
Claude 4 Opus
95.8

GPT-5.5 leads on MMLU and MATH, indicating stronger reasoning-oriented scores. Claude 4 Opus leads on MMLU Pro, GPQA, and HumanEval. 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 Claude 4 Opus tends to split common product tasks based on catalog strengths, price, and modalities.

TaskWinner
CodingClaude 4 Opus
Blog writingGPT-5.5
ResearchClaude 4 Opus
Customer supportGPT-5.5
Cheap API / high volumeGPT-5.5
AI agentsClaude 4 Opus
SummarizationGPT-5.5
TranslationGPT-5.5
Vision / multimodalGPT-5.5
Self-hosting / open weightsGPT-5.5

Technical differences

FeatureGPT-5.5Claude 4 Opus
ProviderOpenAIAnthropic
LicenseProprietaryProprietary
Pricing modeltokenstokens
Context window400k tokens500k tokens
Max output16k tokens32k tokens
Vision inputYesYes
Audio inputNoNo
Text outputYesYes
Image outputNoNo
Video outputNoNo
Audio outputNoNo
Self-host friendlyNoNo
DocsAvailableAvailable

Strengths, weaknesses and best-for

GPT-5.5
Strengths
  • Best-in-class reasoning
  • Huge 400k context
  • Strong tool use and agents
Weaknesses
  • Expensive vs Sonnet for non-reasoning tasks
  • Higher latency than gpt-5.5-mini
Best for
  • Agentic workflows
  • Complex coding
  • Hard math & research
Claude 4 Opus
Strengths
  • Top HumanEval
  • Long, coherent outputs
  • 500k context
Weaknesses
  • Slower than Sonnet
  • Premium price
Best for
  • Long-context coding
  • Tool-using agents
  • Document understanding

Who should choose which

Choose GPT-5.5 if

  • You need stronger reasoning, coding, or math quality
  • You care about faster token throughput
  • API budget is the top constraint
  • Agentic workflows
  • Complex coding

Choose Claude 4 Opus if

  • You need stronger reasoning, coding, or math quality
  • You need a larger context window
  • Long-context coding
  • Tool-using agents

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 Opus

Pros

  • Top HumanEval
  • Long, coherent outputs
  • 500k context

Cons

  • Slower than Sonnet
  • Premium price

Editorial verdict

GPT-5.5 edges this matchup — with caveats

GPT-5.5 is the better choice when you prioritize reasoning, math, speed, and price. Claude 4 Opus stands out for coding and context, 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, Claude 4 Opus 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 Opus review, or open the full AI models table.

GPT-5.5 vs Claude 4 Opus — frequently asked questions

On our scorecard, GPT-5.5 wins overall (leads on Reasoning, Math, Speed, and Price). The “better” model still depends on your workload — validate with your own evals.

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