o3 Pro vs Claude Opus 4.8 — LLM API Cost Comparison
Compare o3 Pro (OpenAI) vs Claude Opus 4.8 (Anthropic) 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
- $20/1M tokens
- Output
- $80/1M tokens
- Context
- 200K tokens
- Released
- 2025-06
o3 Pro; extended thinking compute; top-tier reasoning
- Input
- $5/1M tokens
- Output
- $25/1M tokens
- Context
- 1M tokens
- Released
- 2026-05
Latest Claude Opus; newest flagship from Anthropic
Monthly Cost by Usage Tier (70% input / 30% output ratio)
| Usage | o3 Pro | Claude Opus 4.8 | Cheaper by |
|---|---|---|---|
| Light (1M tokens) | $38.00 | $11.00 | Claude Opus 4.8 (71%) |
| Moderate (10M tokens) | $380 | $110 | Claude Opus 4.8 (71%) |
| Heavy (100M tokens) | $3,800 | $1,100 | Claude Opus 4.8 (71%) |
| Very Heavy (1B tokens) | $38,000 | $11,000 | Claude Opus 4.8 (71%) |
Frequently Asked Questions
Which is cheaper — o3 Pro or Claude Opus 4.8?
For input tokens, Claude Opus 4.8 is cheaper at $5/1M tokens — 4.0× less than $20/1M. For output tokens, Claude Opus 4.8 wins at $25/1M vs $80/1M. At heavy workloads (100M tokens/month), the cost difference can be significant.
What is the context window difference between o3 Pro and Claude Opus 4.8?
o3 Pro supports 200,000 tokens per request; Claude Opus 4.8 supports 1,000,000 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 o3 Pro over Claude Opus 4.8?
Choose o3 Pro (OpenAI) if you prefer OpenAI's ecosystem, tooling, or reliability track record. o3 Pro; extended thinking compute; top-tier reasoning. Choose Claude Opus 4.8 (Anthropic) if Latest Claude Opus; newest flagship from Anthropic. 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 o3 Pro vs Claude Opus 4.8?
At 700M input + 300M output tokens (1B total): o3 Pro costs $38000; Claude Opus 4.8 costs $11000. The difference is $27000/billion tokens at this 70/30 input/output ratio.