GPT-6.1 Terra vs GPT-6 Sol

OpenAI's newest against the GPT-6 tier it refines: Terra asks half Sol's price per token on the same 1,050,000-token window, which makes this a rare upgrade with no trade to weigh.

Figures as of 26 October 2026, read live from the model registry Zeplik bills against.

What the numbers say

• GPT-6.1 Terra is about 2.0x cheaper on output tokens (60.0 vs 120 credits per 1M).
• Both take the same 1.1M-token context window.
• GPT-6.1 Terra is the newer release (October 2026 vs September 2026).

Derived from the live registry Zeplik routes and bills against. Credits: 1 credit = $0.10, computed from the raw provider rate with a 1.20x margin.

Side by side

Try both on Zeplik

The honest answer to most model debates is to run your own prompt on both. Zeplik puts GPT-6.1 Terra and GPT-6 Sol in the same chat, so you can switch mid-conversation and compare answers on the work you actually do.

Frequently asked questions

What is the difference between GPT-6.1 Terra and GPT-6 Sol?

GPT-6.1 Terra is about 2.0x cheaper on output tokens (60.0 vs 120 credits per 1M). Both take the same 1.1M-token context window. GPT-6.1 Terra is the newer release (October 2026 vs September 2026).

Is GPT-6.1 Terra or GPT-6 Sol cheaper?

GPT-6.1 Terra is cheaper: 60.0 credits per million output tokens against 120. 1 credit = $0.10, computed from the raw provider rate with a 1.20x margin.

Which has the larger context window, GPT-6.1 Terra or GPT-6 Sol?

Neither: both take 1.1M tokens.

Can I use both GPT-6.1 Terra and GPT-6 Sol on Zeplik?

Yes. Zeplik is a multi-model chat, so both sit behind one account and you can switch between them mid-conversation to compare answers on your own prompt.

Do GPT-6.1 Terra and GPT-6 Sol need a paid plan?

Both need a paid plan (Plus or above). Usage is then billed in credits from your monthly allowance.

Related comparisons

• Claude Opus 5.5 vs GPT-6 SolBoth shipped on the same day at adjacent tiers: whether Opus 5.5's depth is worth double GPT-6 Sol's price when their context windows are within five percent of each other.
• GPT-6 Sol vs GPT-5.6 SolThe generational swap that also halves the bill: GPT-6 Sol replaces GPT-5.6 Sol at $2 in and $10 out, half what the model it supersedes now asks, on the same 1,050,000-token window.
• GPT-6 Sol vs GPT-6 AstraThe upgrade decision inside the GPT-6 line: Astra costs five times Sol for the same 1,050,000-token window, so the question is which work is hard enough to need it.
• GPT-6 Sol vs GPT-6 LunaGPT-6's capability tier against its value tier, twenty times apart on both input and output price with the same context window on each.
• GPT-6 Sol vs Claude Sonnet 5Priced identically at $2 in and $10 out, five percent apart on context: the closest like-for-like comparison in the catalogue, and a genuine toss-up on price alone.
• GPT-6 Sol vs Grok 4.7Two September flagships a day apart: Grok 4.7 undercuts GPT-6 Sol by half on output, and GPT-6 Sol answers with twice the context window.