GPT-6.1 Terra Pro vs Claude Opus 5.5: API Pricing, Limits & Cost Delta

Side-by-side 2026 engineering comparison between OpenAI GPT-6.1 Terra Pro and Anthropic Claude Opus 5.5—covering uncached input, cached prefix reads, output rates, max completion tokens, and live 30-day workload savings.

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Interactive Workload Cost Delta Simulator

30-Day Spend Delta: GPT-6.1 Terra Pro vs Claude Opus 5.5
GPT-6.1 Terra Pro (30-day)
$183.00/mo
Claude Opus 5.5 (30-day)
$732.00/mo
Monthly cost delta & winner
GPT-6.1 Terra Pro saves $549.00/mo (75% lower)

Side-by-Side Unit Price & Capability Matrix

GPT-6.1 Terra Pro vs Claude Opus 5.5 verified 2026 pricing and technical specification diff
Dimension GPT-6.1 Terra Pro Claude Opus 5.5
Provider & Release DateOpenAI (2026-10-26)Anthropic (2026-09-22)
Primary Workload TierFrontier ReasoningCoding & Agent
Uncached Input ($ / 1M tokens)$1$4
Cached Prompt Read ($ / 1M tokens)$0.05$0.2
Output Completion ($ / 1M tokens)$5$20
50% Async Batch APISupportedSupported
Context Window (tokens)1,050,0001,000,000
Max Output Tokens128,000128,000
Function / Tool CallingSupportedSupported
Strict JSON Schema OutputsSupportedSupported
Reasoning Token ModeSupportedSupported
Accepted Input Modalitiestext, file, imagetext, image, file

Decision Rubric: When to Pick GPT-6.1 Terra Pro vs Claude Opus 5.5

When to choose GPT-6.1 Terra Pro (OpenAI)

Select GPT-6.1 Terra Pro when your workload prioritizes its Frontier Reasoning profile ($1/1M input, $0.05/1M cached read, $5/1M output) with up to 1,050,000 context tokens and 128,000 max output tokens (50% Batch API supported).

GPT-6.1 Terra Pro full pricing sheet →

When to choose Claude Opus 5.5 (Anthropic)

Select Claude Opus 5.5 when your workload prioritizes its Coding & Agent profile ($4/1M input, $0.2/1M cached read, $20/1M output) with up to 1,000,000 context tokens and 128,000 max output tokens (50% Batch API supported).

Claude Opus 5.5 full pricing sheet →

Frequently Asked Questions

Is GPT-6.1 Terra Pro cheaper than Claude Opus 5.5 for production API workloads?

On standard uncached rates, GPT-6.1 Terra Pro bills $1/1M input and $5/1M output versus Claude Opus 5.5 at $4/1M input and $20/1M output. On a typical 1,000 calls/day workload (4,000 input tokens at 50% cache hit + 800 output tokens), GPT-6.1 Terra Pro saves $549.00/month (75% lower).

How do GPT-6.1 Terra Pro and Claude Opus 5.5 compare on context window and max output tokens?

GPT-6.1 Terra Pro offers a 1,050,000-token context window with 128,000 max output tokens (text, file, image), while Claude Opus 5.5 provides a 1,000,000-token context window with 128,000 max output tokens (text, image, file).

Can I switch between GPT-6.1 Terra Pro and Claude Opus 5.5 with strict JSON Schema tool calling?

Both models can be evaluated locally in DevToken: GPT-6.1 Terra Pro (tools: Supported, strict JSON Schema: Supported) vs Claude Opus 5.5 (tools: Supported, strict JSON Schema: Supported). Always verify rate-limit headroom in the 429 Calculator before cutover.