Anthropic: Claude Sonnet 5.5 vs OpenAI: GPT-5.6 Terra Pro
On input price, Anthropic: Claude Sonnet 5.5 is ~1.0× cheaper. Verified 2026-10-21.
Verdict
On blended price (3:1 input:output), Anthropic: Claude Sonnet 5.5 is ~1.1× cheaper ($2.00/$10.00 vs $2.00/$12.00 per 1M tokens).
Pricing
Per-million-token list prices, verified 2026-10-21. Green marks the better value.
| Metric | Anthropic: Claude Sonnet 5.5 | OpenAI: GPT-5.6 Terra Pro |
|---|---|---|
| Input / 1M | $2.00 | $2.00 |
| Output / 1M | $10.00 | $12.00 |
| Cache read / 1M | $0.100 | $0.200 |
| Blended (3:1) | $4.00/1M | $4.50/1M |
| Estimated monthly cost | Anthropic: Claude Sonnet 5.5 | OpenAI: GPT-5.6 Terra Pro |
|---|---|---|
| Chatbot10,000 reqs · 800/400 tok | $56.00 | $64.00 |
| Coding agent5,000 reqs · 8000/2000 tok | $180.00 | $200.00 |
| RAG pipeline30,000 reqs · 4000/500 tok | $390.00 | $420.00 |
Plug in your own numbers in the calculator, or paste a real bill into the Bill Shredder.
Specifications & capabilities
| Metric | Anthropic: Claude Sonnet 5.5 | OpenAI: GPT-5.6 Terra Pro |
|---|---|---|
| Context window | 1M | 1.1M |
| Max output | 128K | 128K |
| 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.
Speed measurements aren't available for both models yet.
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 5.5 pricing · OpenAI: GPT-5.6 Terra Pro pricing