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GPT-5.5 vs GPT-6.1 Terra

GPT-5.5 and GPT-6.1 Terra are closely matched at 47.0 and 47.6 on the LLM Stats Score. GPT-6.1 Terra is 5.6x cheaper per token.

OpenAI · OpenAI · Updated for 2026

Which is better?

GPT-5.5 and GPT-6.1 Terra are closely matched on the overall LLM Stats Score at 47.0 and 47.6.

On price, GPT-6.1 Terra is roughly 5.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT-5.5

  • you want predictable pricing at $5.00/M input and $30.00/M output

Choose GPT-6.1 Terra

  • your work emphasizes agents — it leads those capability indexes
  • cost matters — it's about 5.6x cheaper per token
  • you want the most recent training data — it shipped Oct 2026

At a glance

The differences that matter most.

GPT-5.5
OpenAI
GPT-6.1 Terra
OpenAI
Core performance indexes
LLM Stats Score
47.0
#40
47.6
#37
Reasoning
46.7
#30
49.1
#18
Coding
36.1
#35
37.3
#30
Agents
31.3
#45
38.7
#11
Cost, coverage & limits
Benchmark wins
—
—
Input price
$5.00 / M
$1.00 / M
Output price
$30.00 / M
$5.00 / M
Context window
1,050,000
1,050,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-5.5
GPT-6.1 Terra
Tool use
27.1#32
33.3#5
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

28 reported for GPT-5.5 · 9 for GPT-6.1 Terra

No common benchmarks found

GPT-5.5 and GPT-6.1 Terradon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT-6.1 Terra costs less

For input processing, GPT-5.5 ($5.00/1M tokens) is 5.0x more expensive than GPT-6.1 Terra ($1.00/1M tokens).

For output processing, GPT-5.5 ($30.00/1M tokens) is 6.0x more expensive than GPT-6.1 Terra ($5.00/1M tokens).

In conclusion, GPT-5.5 is more expensive than GPT-6.1 Terra.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Fri Nov 06 2026 • llm-stats.com
OpenAI
GPT-5.5
Input tokens$5.00
Output tokens$30.00
Best providerOpenAI
OpenAI
GPT-6.1 Terra
Input tokens$1.00
Output tokens$5.00
Best providerOpenAI
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Both models have the same input context window of 1,050,000 tokens. Both models can generate responses up to 128,000 tokens.

OpenAI
GPT-5.5
Input1,050,000 tokens
Output128,000 tokens
OpenAI
GPT-6.1 Terra
Input1,050,000 tokens
Output128,000 tokens
Fri Nov 06 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-5.5 and GPT-6.1 Terra support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5.5

Text
Images
Audio
Video

GPT-6.1 Terra

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-5.5

Proprietary

Closed source

GPT-6.1 Terra

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.5 was released on 2026-04-23, while GPT-6.1 Terra was released on 2026-10-26.

GPT-6.1 Terra is 6 months newer than GPT-5.5.

GPT-5.5

Apr 23, 2026

6 months ago

GPT-6.1 Terra

Oct 26, 2026

1 weeks ago

6mo newer

Knowledge Cutoff

When training data ends

GPT-5.5 has a knowledge cutoff of 2025-12-01, while GPT-6.1 Terra has a cutoff of 2026-06-01.

GPT-6.1 Terra has more recent training data (up to 2026-06-01), making it potentially better informed about events through that date compared to GPT-5.5 (2025-12-01).

GPT-5.5

Dec 2025

GPT-6.1 Terra

Jun 2026

6 mo newer

Provider Availability

GPT-5.5 is available from OpenAI. GPT-6.1 Terra is available from OpenAI.

GPT-5.5

openai logo
OpenAI
Input Price:Input: $5.00/1MOutput Price:Output: $30.00/1M

GPT-6.1 Terra

openai logo
OpenAI
Input Price:Input: $1.00/1MOutput Price:Output: $5.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against GPT-5.5 and GPT-6.1 Terra side-by-side, then vote on the output you prefer.

GPT-5.5
✓ Preferred
GPT-6.1 Terra
Open in Playground

FAQ

Common questions about GPT-5.5 vs GPT-6.1 Terra.

Which is better, GPT-5.5 or GPT-6.1 Terra?

GPT-5.5 and GPT-6.1 Terra are closely matched on the LLM Stats Score at 47.0 and 47.6. GPT-5.5 is made by OpenAI and GPT-6.1 Terra is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-5.5 compare to GPT-6.1 Terra in benchmarks?

GPT-5.5 scores Tau2 Telecom: 98.0%, ARC-AGI: 95.0%, GPQA: 93.6%, ARC-AGI v2: 85.0%, GDPval-MM: 84.9%. GPT-6.1 Terra scores HealthBench Consensus: 95.1%, HealthBench Professional: 62.7%, Agents' Last Exam: 60.0%, Terminal-Bench-Science 0.1: 58.3%, MentalHealthBench: 55.5%.

Is GPT-5.5 cheaper than GPT-6.1 Terra?

GPT-6.1 Terra is 5.0x cheaper for input tokens. GPT-5.5 costs $5.00/M input and $30.00/M output via openai. GPT-6.1 Terra costs $1.00/M input and $5.00/M output via openai.

What are the context window sizes for GPT-5.5 and GPT-6.1 Terra?

GPT-5.5 supports 1.1M tokens and GPT-6.1 Terra supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.5 and GPT-6.1 Terra?

Key differences include LLM Stats Score (47.0 vs 47.6), input pricing ($5.00 vs $1.00/M). See the full comparison above for benchmark-by-benchmark results.

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