Claude Opus 4.8 vs GPT-5.5 — LLM API Cost Comparison
Compare Claude Opus 4.8 (Anthropic) vs GPT-5.5 (OpenAI) on cost per million tokens, context window, and monthly spend.
Prices verified 2026-06-06 · Pricing may change — use the calculator for current estimates
- Input
- $5/1M tokens
- Output
- $25/1M tokens
- Context
- 1M tokens
- Released
- 2026-05
Latest Claude Opus; newest flagship from Anthropic
- Input
- $5/1M tokens
- Output
- $30/1M tokens
- Context
- 272K tokens
- Released
- 2026-04
Latest OpenAI frontier model; 272K context standard tier
Monthly Cost by Usage Tier (70% input / 30% output ratio)
| Usage | Claude Opus 4.8 | GPT-5.5 | Cheaper by |
|---|---|---|---|
| Light (1M tokens) | $11.00 | $12.50 | Claude Opus 4.8 (12%) |
| Moderate (10M tokens) | $110 | $125 | Claude Opus 4.8 (12%) |
| Heavy (100M tokens) | $1,100 | $1,250 | Claude Opus 4.8 (12%) |
| Very Heavy (1B tokens) | $11,000 | $12,500 | Claude Opus 4.8 (12%) |
Frequently Asked Questions
Which is cheaper — Claude Opus 4.8 or GPT-5.5?
For input tokens, GPT-5.5 is cheaper at $5/1M tokens — 1.0× less than $5/1M. For output tokens, Claude Opus 4.8 wins at $25/1M vs $30/1M. At heavy workloads (100M tokens/month), the cost difference can be significant.
What is the context window difference between Claude Opus 4.8 and GPT-5.5?
Claude Opus 4.8 supports 1,000,000 tokens per request; GPT-5.5 supports 272,000 tokens. Claude Opus 4.8 wins on context length, making it better for long documents, large codebases, or extended conversations without chunking.
When should I choose Claude Opus 4.8 over GPT-5.5?
Choose Claude Opus 4.8 (Anthropic) if you prefer Anthropic's ecosystem, tooling, or reliability track record. Latest Claude Opus; newest flagship from Anthropic. Choose GPT-5.5 (OpenAI) if Latest OpenAI frontier model; 272K context standard tier. the price/performance fits your workload better. Use this calculator to find the break-even point for your exact token volume.
How much does 1 billion tokens cost on Claude Opus 4.8 vs GPT-5.5?
At 700M input + 300M output tokens (1B total): Claude Opus 4.8 costs $11000; GPT-5.5 costs $12500. The difference is $1500/billion tokens at this 70/30 input/output ratio.