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OpenAI · Performance on a more reasonable budget

GPT-5.6 Terra

A practical compromise for solving complex problems and autonomous programming. Slightly less capable than the Sol variant, but more economical.

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Costs
Upper mid-range · from July 30, 2026, standard pricing is $2 per million input tokens and $12 per million output tokens
Speed
Medium depending on processing thoroughness
Availability
Online service from OpenAI and the Codex tool
Input length
Varies by product and mode
Inputs
Text and, depending on the service used, image inputs

Data checked . Release date unverified.

Indicative capability profile

Where the model is strong

The five levels are our clear summary of the results below. They are not a ranking that applies to every task.

Analysis Very strong logical reasoning, only slightly weaker than Sol.
Coding Strong at coding, including autonomous programming.
Autonomous work across multiple steps Very good at coding tasks in which it uses tools on its own.
Writing and content Good all-round text handling.
Speed A better balance of performance and cost than the top-tier variant.

Ideal use

When to choose it

  • Everyday programming with AI assistance
  • Analyses where costs need to be controlled
  • Second stage after a low-cost classification model

Usage boundaries

When to choose another model

  • The hardest tasks with no opportunity for correction
  • Simple processing at scale where Flash-Lite is sufficient

Traceable supporting sources

Data and measurement sources

Distinguish between the manufacturer's documentation and the results of a specific test. Measurements also depend on the settings and the task set used.

LiveBench

LiveBench 2026-06-25

79.8 overall · 90.6 for problem solving

Performance close to the most expensive variants at a lower cost per successful task.

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LiveBench

Agentic Coding

68.0 points

In this test, it performed better at autonomous coding than the Sol variant.

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OpenAI

Standard price after the price reduction

$2 input · $0.20 cached input · $12 output

Amounts are per million tokens in a short context; the price fell by 20%.

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Trends over time

Related events from AI Radar

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OpenAI major

OpenAI cuts prices for GPT-5.6 Luna and Terra models, says optimization of its own infrastructure by Sol made this possible

Anyone using OpenAI API for their own projects or tools with a low-cost model (Luna) will pay significantly less for the same work than before, as illustrated by Simon Willison, who switched from Gemini to Luna because of the price.

Companies running products on cheaper GPT-5.6 models can reduce inference costs by as much as tens of percent or consider switching from competing providers (Google, Anthropic), intensifying price pressure across the AI industry.

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context

Company Basis: GPT-6 Astra model doubled the speed of tax workbook processing compared to the GPT-5.6 Sol model

For individuals working with large financial or tax spreadsheets, the case study suggests that a newer model may process similar tasks significantly faster, although this is a corporate testimonial, not a publicly available benchmark.

According to the company Basis, deploying the GPT-6 Astra model doubled the processing speed of a large 50-tab tax workbook compared to the GPT-5.6 Sol model, which increases the company's confidence in deploying the model for similar tasks in production.

1 source
Anthropic important

Anthropic has released Claude Opus 5 – a cheaper model close to Fable 5 in performance

Claude Pro and Max users get Opus 5 as the default or most capable available model with no price change; the choice of "effort" level (low to max) directly affects the balance of speed, quality, and cost for individual queries.

Companies deploying Claude in products or development gain a model that, according to Anthropic, comes close to Fable 5 in knowledge work and agentic coding at half the token price, changing the cost calculation for running AI.

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