Anthropic: Claude Sonnet 4.5 vs OpenAI: o3
On input price, OpenAI: o3 is ~1.5× cheaper. Verified 2026-10-21.
Verdict
On blended price (3:1 input:output), OpenAI: o3 is ~1.7× cheaper ($2.00/$8.00 vs $3.00/$15.00 per 1M tokens). Anthropic: Claude Sonnet 4.5 generates 117% faster output.
Pricing
Per-million-token list prices, verified 2026-10-21. Green marks the better value.
| Metric | Anthropic: Claude Sonnet 4.5 | OpenAI: o3 |
|---|---|---|
| Input / 1M | $3.00 | $2.00 |
| Output / 1M | $15.00 | $8.00 |
| Cache read / 1M | $0.300 | $0.500 |
| Blended (3:1) | $6.00/1M | $3.50/1M |
| Estimated monthly cost | Anthropic: Claude Sonnet 4.5 | OpenAI: o3 |
|---|---|---|
| Chatbot10,000 reqs · 800/400 tok | $84.00 | $48.00 |
| Coding agent5,000 reqs · 8000/2000 tok | $270.00 | $160.00 |
| RAG pipeline30,000 reqs · 4000/500 tok | $585.00 | $360.00 |
Plug in your own numbers in the calculator, or paste a real bill into the Bill Shredder.
Specifications & capabilities
| Metric | Anthropic: Claude Sonnet 4.5 | OpenAI: o3 |
|---|---|---|
| Context window | 1M | 200K |
| Max output | 64K | 100K |
| Vision input | ✓ | ✓ |
| Tool calling | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
Quality
Intelligence Index by Artificial Analysis (independent evaluations, 0–100).
Verified intelligence scores aren't available for both models yet. See the full leaderboard.
Performance
Measured by Artificial Analysis on live endpoints.
| Metric | Anthropic: Claude Sonnet 4.5 | OpenAI: o3 |
|---|---|---|
| Cost per task | $0.000008 | $0.000040 |
Provider
Infrastructure metrics for the organizations behind these models.
| Metric | Anthropic | OpenAI |
|---|---|---|
| Listed endpoints | 8 | 12 |
| Reliability | 99.8% | 99.9% |
| Avg latency | 520 ms | 450 ms |
| Pricing tiers | standard, batch | standard, batch, provisioned |
Full details: Anthropic: Claude Sonnet 4.5 pricing · OpenAI: o3 pricing