Claude Sonnet 5 vs GPT-5.6 Terra — Side-by-side pricing
Side-by-side API pricing and tokenizer details for Claude Sonnet 5 (Anthropic) and GPT-5.6 Terra (OpenAI).
Side-by-side pricing
| Feature | Claude Sonnet 5 | GPT-5.6 Terra |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input (per 1M tokens) | $2.00 | $2.50 |
| Output (per 1M tokens) | $10.00 | $15.00 |
| Long-context pricing | Flat rate at any prompt size | Over 272K tokens: $5.00 in / $22.50 out |
| Context caching | Yes — 90% off cached tokens | Yes — 90% off cached tokens |
| Batch API discount | 50% off | 50% off |
| Context window | 1M tokens | 1.1M tokens |
| Tokenizer | Anthropic tokenizer (Opus 4.7+) | o200k_base (tiktoken) |
ⓘ Claude Sonnet 5: Introductory pricing through Aug 31, 2026. Standard price: $3.00 / $15.00 per MTok after that date.
Real-world cost example
1,000 API requests per month, each with 500 input tokens and 200 output tokens (500K input + 200K output total).
Claude Sonnet 5
$3.0000
Input: $1.0000 +Output: $2.0000
GPT-5.6 Terra
$4.2500
Input: $1.2500 +Output: $3.0000
Claude Sonnet 5 is 29% cheaper for this workload — saving $1.2500 per month at this volume.
Frequently asked questions
Yes, Claude Sonnet 5 is cheaper for the typical workload above. At $2.00/1M input and $10.00/1M output tokens, it costs $3.0000 versus $4.2500 for GPT-5.6 Terra — a 29% difference. Note that GPT-5.6 Terra switches to long-context pricing above 272K prompt tokens, so for very long prompts this gap does not scale linearly.
Claude Sonnet 5 supports a 1M token context window. GPT-5.6 Terra supports a 1.1M token context window. A larger context window lets you include more text — documents, conversation history, or code — in a single API call.
Claude Sonnet 5 supports context caching (90% off repeated tokens). It offers a 50% Batch API discount. GPT-5.6 Terra supports context caching (90% off repeated tokens). It offers a 50% Batch API discount.
No, they use different tokenizers. Claude Sonnet 5 uses the Anthropic tokenizer (Opus 4.7+), while GPT-5.6 Terra uses o200k_base (tiktoken). Different tokenizers split text differently, so the same prompt will produce different token counts on each model — the effective cost difference may be larger or smaller than the per-token price difference alone suggests.
Claude Sonnet 5 (Anthropic): $2 input / $10 output per 1M tokens. GPT-5.6 Terra (OpenAI): $2.5 input / $15 output per 1M tokens. Rates shown before caching or batch discounts.
For an 80% output / 20% input workload — typical for code generation or long-form writing — Claude Sonnet 5 costs $8.4000 per 1M total tokens and GPT-5.6 Terra costs $12.5000. Claude Sonnet 5 is 33% cheaper for this pattern. For your exact ratio, paste a real prompt into the calculator above.
Claude Sonnet 5 has a 1M-token context window — approximately 750K words or ~3K pages of standard text. GPT-5.6 Terra has a 1.1M-token context window — approximately 788K words or ~3K pages. (Estimates assume ~0.75 words per token.)
Calculate costs for your actual prompt
Paste your prompt into the calculator and get exact token counts using each model's real tokenizer — all in your browser.
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