Claude Opus 5 vs GPT-5.6 Terra

A side-by-side comparison of Claude Opus 5 and GPT-5.6 Terra: input/output pricing, capabilities and available endpoints, served live from OpenCrow. Both are reachable with the same API key.

Pricing comparison

ItemClaude Opus 5GPT-5.6 Terra
Input (per 1M tokens)$5$1.625
Output (per 1M tokens)$25$9.75
Cache read (per 1M tokens)$0.5$0.1625
Cache write 5m (per 1M tokens)$6.25$2.03125

Specifications

ItemClaude Opus 5GPT-5.6 Terra
Context window1,000,000922,000
Max output128,000128,000

Capability comparison

ItemClaude Opus 5GPT-5.6 Terra
function_callingYesYes
prompt_cachingYesYes
visionYesYes

Which should you pick

Which is cheaper, Claude Opus 5 or GPT-5.6 Terra?

On input, GPT-5.6 Terra is cheaper ($5 vs $1.625 per 1M tokens). On output, GPT-5.6 Terra is cheaper ($25 vs $9.75 per 1M tokens). All prices are per million tokens in USD.

Which has the larger context window, Claude Opus 5 or GPT-5.6 Terra?

Claude Opus 5 does — Claude Opus 5 accepts 1,000,000 input tokens and GPT-5.6 Terra accepts 922,000.

What can Claude Opus 5 do that GPT-5.6 Terra cannot?

both support function_calling, prompt_caching, vision.

Can I switch between Claude Opus 5 and GPT-5.6 Terra without changing my code?

Yes. Both are available on OpenCrow through one API key and the same OpenAI-compatible endpoint — switching means changing the model field from "claude-opus-5" to "gpt-5.6-terra", nothing else.

Both are available on OpenCrow under one API key — switching between them means changing the model field and nothing else, so you can use each where it fits rather than picking one.

Claude Opus 5 · GPT-5.6 Terra · All models