Skip to content

Claude Opus 5 (Fast) vs GPT-5.5 Pro

vs
GPT-5.5 Pro

OpenAI

93#8
Signal-by-Signal Comparison
SignalClaude Opus 5 (Fast)DeltaGPT-5.5 Pro
Capabilities
100
--
100
Pricing
50
+45
5
Context window size
95
0
96
Recency
100
--
100
Output Capacity
85
--
85
Benchmarks
0
-92
92
Overall Result
1 wins
of 6
2 wins
GPT-5.5 Pro wins 2 of 6 signals

Score History

Score History (15 data points)
Claude Opus 5 (Fast)GPT-5.5 Pro
Claude Opus 5 (Fast)

95.1

current score

Leader

Claude Opus 5 (Fast)

right now

GPT-5.5 Pro

92.7

current score

LMMarketCap.com
Interactive Price Comparison
100Kcalls/month
1,000tokens (~1,333 chars)
500tokens (~667 chars)

Claude Opus 5 (Fast)

Anthropic

Best Value
Per request$0.035000
Daily$116.67
Monthly$3500.00
Annual$42000.00

GPT-5.5 Pro

OpenAI

Per request$0.120000
Daily$400.00
Monthly$12000.00
Annual$144000.00

Claude Opus 5 (Fast) saves you $8500.00/month

That's $102000.00/year compared to GPT-5.5 Pro at your current usage level of 100K calls/month.

71% cheaper
Choose Claude Opus 5 (Fast) for cost optimization

Claude Opus 5 (Fast) pricing:
Input:$10.00/M tokens
Output:$50.00/M tokens
GPT-5.5 Pro pricing:
Input:$30.00/M tokens
Output:$180.00/M tokens
Winner
Claude Opus 5 (Fast)

Anthropic

95

Composite Score

GPT-5.5 Pro

OpenAI

93

Composite Score

Signal-by-Signal Comparison
MetricClaude Opus 5 (Fast)GPT-5.5 ProWinner
Overall Score
95
93
Claude Opus 5 (Fast)
Rank#2#8
Claude Opus 5 (Fast)
Quality Rank#2#8
Claude Opus 5 (Fast)
Adoption Rank#2#8
Claude Opus 5 (Fast)
Parameters------
Context Window1000K1050K
GPT-5.5 Pro
Pricing$10.00/$50.00/M$30.00/$180.00/M--
Signal Scores
Capabilities
100
100
Claude Opus 5 (Fast)
Pricing
50
5
Claude Opus 5 (Fast)
Context window size
95
96
GPT-5.5 Pro
Recency
100
100
Claude Opus 5 (Fast)
Output Capacity
85
85
Claude Opus 5 (Fast)
Benchmarks--
92
GPT-5.5 Pro
Benchmark Head-to-Head(3 benchmarks)
Claude Opus: 0GPT-5.5 Pro: 0
Claude Opus
GPT-5.5 Pro
Normalized 0-100%
MMLU
-92.4%
GPQA Diamond
-93.6%
SWE-bench Verified
-88.7%
Benchmark Interpretation

Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.

Claude Opus 5 (Fast)Elite Tier

Scores 95/100 (rank #2), placing it in the top 100% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
GPT-5.5 ProElite Tier

Scores 93/100 (rank #8), placing it in the top 98% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100

With only a 2-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.

When to Use Each Model

Choose Claude Opus 5 (Fast) when you need:

  • High-volume production workloads where API costs must be minimized
  • Step-by-step reasoning and chain-of-thought problem solving

Choose GPT-5.5 Pro when you need:

  • Step-by-step reasoning and chain-of-thought problem solving
Cost-Performance Analysis
Claude Opus 5 (Fast)Best Value
Input cost$10.00/M tokens
Output cost$50.00/M tokens
Cost per quality point$0.631
Est. monthly (1M tokens/day)$900.00
GPT-5.5 Pro
Input cost$30.00/M tokens
Output cost$180.00/M tokens
Cost per quality point$2.265
Est. monthly (1M tokens/day)$3150.00

Claude Opus 5 (Fast) offers 71% better value per quality point. At 1M tokens/day, you'd spend $900.00/month with Claude Opus 5 (Fast) vs $3150.00/month with GPT-5.5 Pro - a $2250.00 monthly difference.

Latency & Speed
Claude Opus 5 (Fast)Faster
Speed score0/100
GPT-5.5 Pro
Speed score0/100

Both models have comparable response speeds. For most applications, the latency difference is negligible.

When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.

Example Use Cases

Code generation & review

Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring

Claude Opus 5 (Fast)

Customer support chatbot

Suitable for user-facing chat with competitive response times. Claude Opus 5 (Fast) also offers lower per-token costs for high-volume support

Claude Opus 5 (Fast)

Long document analysis

Larger context window (1050K tokens) can process longer documents, contracts, and research papers in a single pass

GPT-5.5 Pro

Batch data extraction

Lower output pricing ($50.00/M) reduces costs when processing thousands of records daily

Claude Opus 5 (Fast)

Creative writing & content

Higher overall composite score (95/100) correlates with better nuance, coherence, and style in long-form content

Claude Opus 5 (Fast)

Image understanding & OCR

Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly

Claude Opus 5 (Fast)
Which Should You Choose?
Our recommendation:
Claude Opus 5 (Fast)

Claude Opus 5 (Fast) and GPT-5.5 Pro are extremely close in overall performance (only 2.3999999999999915 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.

by Anthropic

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Cost - 71% lower pricing; better value at scale
  • Choose for Reliability - Higher uptime and faster response speeds
  • Choose for Prototyping - Stronger community support and better developer experience
  • Choose for Production - Wider enterprise adoption and proven at scale

by OpenAI

Consider for specialized use cases.

Capability Comparison
CapabilityClaude Opus 5 (Fast)GPT-5.5 Pro
Vision (Image Input)
Function Calling
Streaming
JSON Mode
Reasoning
Web Search
Image Output
Monthly Cost Calculator
1,000tokens (600 in / 400 out)
100requests/day (3,000/month)

Claude Opus 5 (Fast)

Anthropic

Best Value
$78.00
estimated monthly cost

GPT-5.5 Pro

OpenAI

$270.00
estimated monthly cost

Claude Opus 5 (Fast) saves you $192.00/month

That's 71% cheaper than GPT-5.5 Pro at 1,000 tokens/request and 100 requests/day.

Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.

Parameters & Context
ParameterClaude Opus 5 (Fast)GPT-5.5 Pro
Context Window1M1.1M
Max Output Tokens128,000128,000
Open SourceNoNo
CreatedJul 24, 2026Apr 24, 2026
Last updated: 56m ago

Related comparisons

Claude Opus 5 (Fast) vs GPT-5.5 Pro (2026) | LM Market Cap