Model comparison

vs

GPT-6.1 Terra vs GPT-6.1 Sol

Two OpenAI models, compared on listed price, real workload cost, context and capabilities.

The short answer

  • GPT-6.1 Terra lists lower input and output prices.
  • GPT-6.1 Terra reads cached input for less ($0.05/M against GPT-6.1 Sol's $0.1/M), which decides the bill for agents that resend long context.

Side-by-side specs

SpecGPT-6.1 TerraGPT-6.1 Sol
ProviderOpenAIOpenAI
Input price$1/M$2/M
Output price$5/M$10/M
Cached input$0.05/M$0.1/M
Blended price (3:1)$2/M$4/M
Context window1M tokens1M tokens
Max output128k tokens128k tokens
InputText, ImagesText, Images
Structured outputYesYes
WeightsClosedClosed
ReleasedOctober 26, 2026September 29, 2026

Same work, both models

WorkloadGPT-6.1 TerraGPT-6.1 Sol
One chat reply3,000 tokens in, 500 outGPT-6.1 Sol costs 2.0× as much as GPT-6.1 Terra$0.0055$0.01
Summarise a 100-page report50,000 tokens in, 1,500 out, one request$0.06$0.12
1,000 classification calls500 tokens in, 20 out, per call$0.60$1.20
Coding-agent session2M tokens in across ~60 turns, 60,000 out, no cache$2.30$4.60
Same session, cached85% of input read from the prompt cache, the rest written to it$0.76$1.52

At listed rates. Token counts are typical sizes, not measurements.

GPT-6.1 Terra pricing notes

  • Requests over 272K input tokens bill the entire request at 2x the input and cache rates and 1.5x the output rate; the listed price is the short-context rate.
  • Cache hits bill at $0.05 per 1M tokens; cache writes cost $1.25 (30-minute) or $2.50 (12-hour).

GPT-6.1 Sol pricing notes

  • Requests over 272K input tokens bill the entire request at 2x the input and cache rates and 1.5x the output rate; the listed price is the short-context rate.
  • Cache hits bill at $0.10 per 1M tokens, half GPT-6 Sol's $0.20; cache writes cost $2.50 (30-minute) or $5.00 (12-hour).

When to pick which

GPT-6.1 Terra

OpenAI's GPT-6.1 Terra is a fast, efficient model for visual reasoning, precise computer use and natural writing. At $1 / $5 it costs half of GPT-6.1 Sol and sits above GPT-6 Luna; it replaces GPT-5.6 Terra.

Pick it if

  • your prompts mix text and images and you want half of GPT-6.1 Sol's token price
  • you resend long prompts; cache hits bill at 5% of input
  • you want reasoning switched off entirely; Terra accepts reasoning effort none

Skip it if

  • GPT-6 Luna at $0.10 / $0.50 covers your workload
  • your prompts often pass 272K input tokens; the whole request then bills higher

GPT-6.1 Sol

OpenAI's GPT-6.1 Sol, for complex coding and professional work, replaced GPT-6 Sol at the same $2 / $10 rate with half Sol's cache-hit price. It sits below GPT-6 Astra and above GPT-6 Luna in price.

Pick it if

  • you want complex coding work at one-fifth of GPT-6 Astra's token price
  • you resend long prompts; cache hits bill at 5% of input
  • your prompts mix text and images

Skip it if

  • GPT-6 Luna at $0.10 / $0.50 covers your workload
  • your prompts often pass 272K input tokens; the whole request then bills higher

FAQ

Which is cheaper, GPT-6.1 Terra or GPT-6.1 Sol?

GPT-6.1 Terra lists lower input and output prices. On a coding-agent session (2M tokens in, 60,000 out) GPT-6.1 Terra costs $2.30 and GPT-6.1 Sol $4.60.

Can I switch between GPT-6.1 Terra and GPT-6.1 Sol mid-task?

Yes. In an Octomind session, /model octohub:gpt-6.1-terra and /model octohub:gpt-6.1-sol switch models without losing the conversation, so you can draft on one and review on the other.

Try either model

Switch between models inside the same Octomind session.

Prices from the catalog of 2026-10-27