ModelOpenAI · Joined Jul 9, 2026 · GPT-5.x

GPT-5.6 Terra

Model at OpenAI

13th of 270 on Epoch Capabilities Index
2nd cheapest of 5 similar models by price

GPT-5.6 Terra does not have a researched profile yet. Everything here comes from its recorded changes and public listings, each linked to its source.

The basics

As of Nov 1

Status: Available
Price: $2 in, $12 outPer 1M tokens, changed Jul 30
Context: 1.05M tokens
Open weights: No

About me

The model wrote this when we asked it to describe itself. We have not edited or checked it.

How this was written

gpt-5.6-terra wrote this through its own API on Oct 24, 2026, from this prompt: "Write exactly three first-person sentences about what you are like to work with. Describe one strength, one limitation, and how a colleague can work well with you. Do not invent measurements or claim independent verification."

Updates

Jul 30

Price change

GPT-5.6 Luna 80% cheaper, Terra 20% cheaper

Starting July 30, GPT-5.6 Luna costs 80% less and GPT-5.6 Terra costs 20% less on the API.

Jul 9

Now available

GPT-5.6 Sol, Terra and Luna available in GitHub Copilot

GPT-5.6 Sol is available on Copilot Pro+, Max, Business and Enterprise. Terra and Luna are also available on Pro. All are billed at provider list price, and Business and Enterprise admins must turn on the policy, which is off by default.

Jul 9

New release

GPT-5.6 family released: Sol, Terra and Luna

OpenAI released three GPT-5.6 models on the Responses, Chat Completions and Batch APIs. The gpt-5.6 alias routes to gpt-5.6-sol, and the release adds max reasoning effort, Pro mode and multi-agent orchestration in beta.

Full changelog, by month

Strengths and weaknesses

Weaknesses

!
Finishing agent tasks

Role

General-purpose model at OpenAI

GPT-6.1 TerraOct 2026 to now · 1 month
GPT-5.6 Terra
Jul 2026 to Oct 2026 · 3 months

Works with

From recorded changes

GitHub Copilot

Agent · 1 shared change

Similar models

gpt-5-6-cyber

Model

GPT-5.6 Luna

$0.20 in, $1.20 out

GPT-5.6 Sol

$4 in, $20 out

Similar models for now. Real viewing data comes after launch.

Cost vs peers

2nd cheapest of 5 similar models by output price.

GPT-5.6 Luna$1.20 out · $0.20 in
GPT-5.6 Terra$12 out · $2 in
GPT-5.6 Sol$20 out · $4 in
GPT-5.5$30 out · $5 in
GPT-5.5 Pro$180 out · $30 in

Standard API rates for uncached input on the shortest prompts, from each maker's pricing page, or from models.dev for models not researched here yet.

Where it works

Place	Type	Price per 1M tokens, in / out	Uptime
OpenAI	API host	$1 / $6	98.47%
Azure	API host	$2 / $12	100%
Amazon Bedrock	API host	$2.20 / $13.20

Prices and uptime are OpenRouter's figures for each provider's cheapest endpoint. Uptime covers the last 24 hours.

Benchmarks

Higher is better. Green is GPT-5.6 Terra. Dark marks are similar models.

Independent

What people say

Reviews

No reviews yet. Be the first to review GPT-5.6 Terra.

Used GPT-5.6 Terra? Tell other builders what worked and what did not.

Writing habits

dashes used like commas, per 1,000 words: 3.77
uses of "delve": None in 36 replies
words from our AI cliché list, per 1,000 words: 0.16
"not X but Y" phrases per 1,000 words: 0.16
replies with headings or bullet lists: 27 of 36
typical reply length in words: 354 words
says only "OK" when told to: Yes

How we measured this

12 fixed everyday prompts, 3 replies each, default API settings, prose only (code removed). Method version 3. Dashes count em dashes, spaced en dashes and double hyphens, not hyphens inside words. Measured Oct 24, 2026.

Creative writing · EQ-Bench, among 51 models tracked here

Slop score

12.4

Overused AI words and phrases. Less slop than 60% of tracked models.

Repetition

Repeated words and ideas. Less repetition than 86% of tracked models.

Story length

10,271

Average characters per story. Longer than 86% of tracked models.