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GPT-5.6 Terra vs GPT-6 Sol Pro

Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.

OpenRouter + LiveBenchAll comparisonsFull leaderboard

GPT-6 Sol Pro is the cheaper of the two; neither can be ranked on quality here.

GPT-6 Sol Pro does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

openai

GPT-5.6 Terra

Blended / 1M
$4.50
Context
1.1M
Released
Jul 9, 2026
Overall score
77.9
reasoningtool callingfile inputimage inputprompt caching

openai

GPT-6 Sol Pro

Blended / 1M
$4.00
Context
1.1M
Released
Sep 22, 2026
Overall score
Not evaluated
reasoningtool callingfile inputimage inputprompt caching

Specs and pricing

MetricGPT-5.6 TerraGPT-6 Sol Pro
LiveBench overall

Mean of the seven LiveBench category scores, 0–100. Higher is better.

77.9
Cost per point

Measured benchmark spend divided by overall score — dollars per point of capability.

$0.1939
Blended price / 1M

3:1 input:output mix, the usual shape of production traffic.

$4.50$4.00win
Input price / 1M$2.00$2.00
Output price / 1M$12.00$10.00win
Cached input / 1M

Price of an input token served from the prompt cache, where the provider publishes one.

$0.200$0.200
Context window1.1M1.1M
Max output tokens128K128K

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — GPT-5.6 Terra on top, GPT-6 Sol Pro below, both out of 100.

Agentic coding
54.9
Coding
78.2
Reasoning
90.6
Mathematics
94.9
Data analysis
79.3
Language
82.9
Instruction following
64.6

What each one costs to run

Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.

WorkloadGPT-5.6 TerraGPT-6 Sol Pro
Support chatbot

1.2K in / 400 out × 200K requests

$1,310/mo$1,150/mo
RAG assistant

8K in / 600 out × 100K requests

$1,600/mo$1,480/mo
Coding agent

40K in / 4K out × 20K requests

$1,552/mo$1,392/mo
Document extraction

20K in / 1.5K out × 50K requests

$2,810/mo$2,660/mo
Bulk classification

500 in / 20 out × 5M requests

$5,300/mo$5,100/mo
Run these two through the cost calculator

Which should you pick?

You are cost-constrained

GPT-6 Sol Pro

Cheaper on blended list price at $4.00 per million tokens.

GPT-5.6 Terra vs GPT-6 Sol Pro FAQ

Which is better, GPT-5.6 Terra or GPT-6 Sol Pro?

GPT-6 Sol Pro is the cheaper of the two; neither can be ranked on quality here. GPT-6 Sol Pro does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

Is GPT-5.6 Terra cheaper than GPT-6 Sol Pro?

GPT-6 Sol Pro is cheaper. On a 3:1 input:output blend, GPT-5.6 Terra lists at $4.50 per million tokens and GPT-6 Sol Pro at $4.00 — GPT-6 Sol Pro is 13% cheaper. Input and output are priced separately — GPT-5.6 Terra charges $2.00 in and $12.00 out, GPT-6 Sol Pro charges $2.00 and $10.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.

Does GPT-5.6 Terra or GPT-6 Sol Pro have a bigger context window?

They are effectively the same — 1.1M for GPT-5.6 Terra and 1.1M for GPT-6 Sol Pro.

Do GPT-5.6 Terra and GPT-6 Sol Pro support prompt caching?

Both publish a cached-input rate: $0.200 per million for GPT-5.6 Terra and $0.200 for GPT-6 Sol Pro, against full input rates of $2.00 and $2.00. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.

Related comparisons

How these numbers are produced

  • Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
  • ScoresLiveBench release 2026-06-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
  • Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
  • “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.

Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.