// head_to_head

GPT-5.6 Terra Pro vs GPT-6 Sol

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 is the cheaper of the two; neither can be ranked on quality here.

Neither model has 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 Pro

Blended / 1M
$4.50
Context
1.1M
Released
Jul 9, 2026
Overall score
Not evaluated
reasoningtool callingfile inputimage inputprompt caching

openai

GPT-6 Sol

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 Terra ProGPT-6 Sol
LiveBench overall

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

Cost per point

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

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

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 Terra ProGPT-6 Sol
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

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

GPT-5.6 Terra Pro vs GPT-6 Sol FAQ

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

GPT-6 Sol is the cheaper of the two; neither can be ranked on quality here. Neither model has 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 Pro cheaper than GPT-6 Sol?

GPT-6 Sol is cheaper. On a 3:1 input:output blend, GPT-5.6 Terra Pro lists at $4.50 per million tokens and GPT-6 Sol at $4.00 — GPT-6 Sol is 13% cheaper. Input and output are priced separately — GPT-5.6 Terra Pro charges $2.00 in and $12.00 out, GPT-6 Sol 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 Pro or GPT-6 Sol have a bigger context window?

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

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

Both publish a cached-input rate: $0.200 per million for GPT-5.6 Terra Pro and $0.200 for GPT-6 Sol, 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.