GPT-5.6 Sol vs GPT-6.1 Terra
GPT-5.6 Sol and GPT-6.1 Terra are closely matched at 52.7 and 47.5 on the LLM Stats Score. GPT-6.1 Terra is 5.6x cheaper per token.
OpenAI · OpenAI · Updated for 2026
Which is better?
GPT-5.6 Sol and GPT-6.1 Terra are closely matched on the overall LLM Stats Score at 52.7 and 47.5.
The models split the 6 individual benchmarks reported for both models evenly.
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-5.6 Sol
- you want predictable pricing at $5.00/M input and $30.00/M output
Choose GPT-6.1 Terra
- 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.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
45 reported for GPT-5.6 Sol · 8 for GPT-6.1 Terra
GPT-5.6 Sol outperforms in 3 benchmarks (HealthBench, HealthBench Consensus, HealthBench Hard), while GPT-6.1 Terra is better at 3 benchmarks (Agents' Last Exam, HealthBench Professional, Terminal-Bench 4.0).
Both models are evenly matched across the benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.6 Sol ($5.00/1M tokens) is 5.0x more expensive than GPT-6.1 Terra ($1.00/1M tokens).
For output processing, GPT-5.6 Sol ($30.00/1M tokens) is 6.0x more expensive than GPT-6.1 Terra ($5.00/1M tokens).
In conclusion, GPT-5.6 Sol is more expensive than GPT-6.1 Terra.*
* Using a 3:1 ratio of input to output tokens
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.
Input capabilities
Documented input modalities across available providers
Both GPT-5.6 Sol and GPT-6.1 Terra support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.6 Sol
GPT-6.1 Terra
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-5.6 Sol was released on 2026-07-09, while GPT-6.1 Terra was released on 2026-10-26.
GPT-6.1 Terra is 4 months newer than GPT-5.6 Sol.
Jul 9, 2026
3 months ago
Oct 26, 2026
3 days ago
3mo newerKnowledge Cutoff
When training data ends
GPT-5.6 Sol has a knowledge cutoff of 2026-02-16, 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-5.6 Sol (2026-02-16).
Feb 2026
Jun 2026
4 mo newerProvider Availability
GPT-5.6 Sol is available from OpenAI. GPT-6.1 Terra is available from OpenAI.
GPT-5.6 Sol
GPT-6.1 Terra
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.6 Sol and GPT-6.1 Terra side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.6 Sol vs GPT-6.1 Terra.