GPT-⁠6 Astra

Q: What is GPT-6 Astra?

GPT-6 Astra is OpenAI's most capable GPT-6 model, released on September 3, 2026. It is built for coding, science, long professional tasks and computer use. It reads up to 1 million tokens of text, images and files and writes up to 128,000 tokens in one reply.

Q: Is GPT-6 Astra available?

Yes. GPT-6 Astra is in OpenAI's apps for paid plans, in Codex and in the OpenAI API as gpt-6-astra, as well as on Microsoft Azure and AWS Bedrock. On Overchat AI you pick it in the model menu of the chat on the web and in the iOS app.

Q: How good is GPT-6 Astra?

GPT-6 Astra scores 57 on the Artificial Analysis Intelligence Index, #4 of 57 models, behind Claude Fable 5.2 (65), Gemini 4 Carbon (60) and Claude Opus 5.5 (59). It has the best GPQA Diamond score of all 325 models tested, 96.1%, and beats GPT-6.1 Sol and GPT-6.1 Terra on coding, science and workflow tests.

Q: Is GPT-6 Astra better than Claude Opus 5.5?

At science and long PDFs, yes: GPT-6 Astra scores 63.3% on Terminal-Bench-Science against 59.0% and 31.0% on GDP.pdf against 26.2%. Claude Opus 5.5 is ahead at hard coding tasks (46.4% against 42.4% on FrontierCode 2.0) and knowledge-work tasks (1801 against 1569 Elo on AA-Briefcase), and it scores 59 on the Intelligence Index against 57.

Q: What is GPT-6 Astra Pro?

GPT-6 Astra Pro is the same model in a longer reasoning mode. It thinks through a complex task for longer and spends more tokens on it, which helps with the hardest problems and slows down everyday answers.

Q: Can GPT-6 Astra read images and files?

Yes. GPT-6 Astra reads text, images and files such as PDFs, spreadsheets and screenshots and answers in text. It doesn't make pictures: for an image, switch to GPT Image 2.6 in the same chat.

Q: What is the context window of GPT-6 Astra?

GPT-6 Astra reads up to 1 million tokens in one conversation, about 750,000 words, and writes up to 128,000 tokens in one reply.

OpenAI's most capable GPT-⁠6 model for coding, science and long professional tasks, with a 1M-⁠token context window

About GPT-⁠6 Astra

GPT-⁠6 Astra is OpenAI's most capable GPT-⁠6 model, released on September 3, 2026. It is built for coding, science and long professional tasks, reads up to 1 million tokens of text, images and files and writes up to 128,000 tokens in one reply

GPT-⁠6 Astra scores 96.1% on GPQA Diamond, graduate-level science questions, the best result of 325 models, and 98% on FrontierMath Tier 4, a set of research-level math problems. It is also the strongest GPT-⁠6 model at coding and business workflows, with 59.1% on Terminal-Bench 4.0 and 68.5% on AutomationBench

On Overchat AI, GPT-⁠6 Astra shares the chat with GPT-⁠6.1 Sol, Claude Opus 5.5 and other models: pick it in the model menu, or let Superchat choose the model for each task

Developer

OpenAI

Released

Sep 3, 2026

Context window

1M tokens

Max output

128,000 tokens

Input

Text, images and files

Output

Text

Reasoning

Adjustable effort, from low to max

Intelligence Index

57, #4 of 57 models

Available in

Codex, OpenAI API, Microsoft Azure, AWS Bedrock, OpenRouter, Overchat AI

Modalities
Intelligence Index?: 57
Context window?: 1M tokens
Released: Sep 3, 2026

GPT-⁠6 Astra vs other models

GPT-⁠6 Astra ranks #4 on the Artificial Analysis Intelligence Index out of 57 models

Artificial Analysis Intelligence Index57#4 of 57 modelsBetter than 92% of 57 models

#1of 325 modelsGPQA DiamondGraduate-level questions in biology, chemistry and physics96.1%
#3of 288 modelsCritPtResearch-level physics problems31.7%
#5of 130 modelsTerminal-Bench 4.0Hard tasks an agent completes in a terminal59.1%
#8of 344 modelsHumanity's Last ExamExpert-level questions across many subjects54.7%

Source: Artificial Analysis

Compare GPT-⁠6 Astra

GPT-6 Astra vs GPT-6.1 Sol

GPT-⁠6 Astra scores higher than GPT-⁠6.1 Sol in 4 of 5 benchmarks. The widest lead is in Terminal-Bench-Science 0.1: 63.3% against 58.1%. GPT-⁠6 Astra writes 48 tokens per second, GPT-⁠6.1 Sol writes 58

Benchmarks won: GPT-6 Astra: 4; GPT-6.1 Sol: 1
Average score: GPT-6 Astra: 52.9%; GPT-6.1 Sol: 50.1%
Output speed, tokens/s: GPT-6 Astra: 48; GPT-6.1 Sol: 58
Time to first token, s (log scale): GPT-6 Astra: 3.2; GPT-6.1 Sol: 2.9

GPT-6.1 Sol aheadGPT-6 Astra ahead

Terminal-Bench-Science 0.1+5.2
AutomationBench+3.6
Terminal-Bench 4.0+3.0
FrontierCode 2.0+1.8
GDP.pdf0.0

GPT-6 Astra vs GPT-6.1 Terra

GPT-⁠6 Astra scores higher than GPT-⁠6.1 Terra in 5 of 5 benchmarks. The widest lead is in AutomationBench: 68.5% against 60.2%. GPT-⁠6 Astra writes 48 tokens per second, GPT-⁠6.1 Terra writes 75

Benchmarks won: GPT-6 Astra: 5; GPT-6.1 Terra: 0
Average score: GPT-6 Astra: 52.9%; GPT-6.1 Terra: 48.9%
Output speed, tokens/s: GPT-6 Astra: 48; GPT-6.1 Terra: 75
Time to first token, s (log scale): GPT-6 Astra: 3.2; GPT-6.1 Terra: 4.3

GPT-6.1 Terra aheadGPT-6 Astra ahead

AutomationBench+8.3
Terminal-Bench-Science 0.1+5.7
Terminal-Bench 4.0+3.5
GDP.pdf+2.4
FrontierCode 2.0+0.1

GPT-6 Astra vs Claude Opus 5.5

GPT-⁠6 Astra scores higher than Claude Opus 5.5 in 2 of 5 benchmarks. The widest lead is in GDP.pdf: 31.0% against 26.2%. Claude Opus 5.5 is ahead in FrontierCode 2.0: 46.4% against 42.4%. GPT-⁠6 Astra writes 48 tokens per second, Claude Opus 5.5 writes 88

Benchmarks won: GPT-6 Astra: 2; Claude Opus 5.5: 3
Average score: GPT-6 Astra: 52.9%; Claude Opus 5.5: 52.1%
Output speed, tokens/s: GPT-6 Astra: 48; Claude Opus 5.5: 88
Time to first token, s (log scale): GPT-6 Astra: 3.2; Claude Opus 5.5: 1.9

Claude Opus 5.5 aheadGPT-6 Astra ahead

GDP.pdf+4.8
Terminal-Bench-Science 0.1+4.3
Terminal-Bench 4.0−0.5
AutomationBench−1.0
FrontierCode 2.0−4.0

GPT-6 Astra vs Claude Sonnet 5.5

GPT-⁠6 Astra scores higher than Claude Sonnet 5.5 in 3 of 5 benchmarks. The widest lead is in Terminal-Bench-Science 0.1: 63.3% against 53.3%. Claude Sonnet 5.5 is ahead in Terminal-Bench 4.0: 63.6% against 59.1%. GPT-⁠6 Astra writes 48 tokens per second, Claude Sonnet 5.5 writes 102

Benchmarks won: GPT-6 Astra: 3; Claude Sonnet 5.5: 2
Average score: GPT-6 Astra: 52.9%; Claude Sonnet 5.5: 51.2%
Output speed, tokens/s: GPT-6 Astra: 48; Claude Sonnet 5.5: 102
Time to first token, s (log scale): GPT-6 Astra: 3.2; Claude Sonnet 5.5: 1.0

Claude Sonnet 5.5 aheadGPT-6 Astra ahead

Terminal-Bench-Science 0.1+10.0
GDP.pdf+5.2
FrontierCode 2.0+0.7
AutomationBench−3.3
Terminal-Bench 4.0−4.5

Best model by use case

Average benchmark scores of GPT-⁠6 Astra and 4 other models by use case

Coding
?Average of 3 tests
1. 1Claude Opus 5.555.0%
2. 2GPT-6 Astra54.9%
3. 3Claude Sonnet 5.552.9%
4. 4GPT-6.1 Terra51.8%
5. 5GPT-6.1 Sol51.6%
Agents
?AutomationBench
1. 1Claude Sonnet 5.571.8%
2. 2Claude Opus 5.569.5%
3. 3GPT-6 Astra68.5%
4. 4GPT-6.1 Sol64.9%
5. 5GPT-6.1 Terra60.2%
Knowledge work
?GDP.pdf
1. 1GPT-6 Astra31.0%
2. 2GPT-6.1 Sol31.0%
3. 3GPT-6.1 Terra28.6%
4. 4Claude Opus 5.526.2%
5. 5Claude Sonnet 5.525.8%

GPT-⁠6 Astra benchmarks

Compare GPT-⁠6 Astra with 4 other models in 6 benchmarks measuring coding, agents and knowledge work

Order

Coding

Terminal-Bench 4.0?59.1%−4.5
FrontierCode 2.0?42.4%−4.0
Terminal-Bench-Science 0.1?63.3%+4.3

Agents

AutomationBench?68.5%−3.3

Knowledge work

AA-Briefcase?1569.0%−248.0
GDP.pdf?31.0%+0.0

Sources: OpenAI, GPT-6 Astra: A new generation of intelligence (Sep 3, 2026), Artificial Analysis, GPT-6 Astra

GPT-⁠6 Astra speed

Output speed is how fast the model writes (tokens per second, higher is better). Time to first token is how long you wait before the answer starts (lower is better)

Output speed and time to first token of 35 models

?Percentile

Time to first token, s (log scale)

Output speed, tokens/s (log scale)

Output speed and time to first token of 35 models
Models	Output speed, tokens/s (log scale)	Time to first token, s (log scale)
GPT-6 Luna	143	2.4
GPT-6.1 Terra	75	4.3
GPT-6.1 Sol	58	2.9
GPT-6 Astra	48	3.2
Claude Opus 5.5	88	1.9
Claude Opus 5	54	2.6
Claude Opus 4.8	59	1.3
Claude Fable 5.2	84	2.3
Claude Sonnet 5.5	102	1
Claude 5 Sonnet	215	10.5
Claude Sonnet 4.6	220	10.8
Claude Haiku 5.5	167	2.1
Gemini 4 Carbon	169	29.5
Gemini 4 Argon	91	6
Gemini 3.8 Flash	203	7.5
Gemini 3 Pro	270	11.2
Grok 4.7	81	8.9
Grok 4.6	290	32
Qwen 3.8 Max	81	30.6
DeepSeek V4 Pro	144	1.1
DeepSeek V4.1 Flash	422	2.2
Mistral Large 4	226	8.6
Hy4	214	37.7
ERNIE 5.5 Flash	405	2.7
Muse Wonder	980	8.7
Muse Spark	1129	6.2
Kimi K3.1 Pro	340	7.4
Kimi K3	338	5.9
GLM 5.3	197	1.2
Flint	194	12.3
Llama 4	81	0.7
Claude 4.5 Haiku	162	0.9
MiniMax M3	169	4.5
MiniMax M3.1 Flash	656	7.2
Kimi K2.7 Code	455	3.6

Typing test

Every model writes the same answer. The test waits the model's time to first token, then prints the text at the model's output speed and shows the total time

Answer length

GPT-6 Astra48 tokens/s3.2 s to first token
GPT-6.1 Sol58 tokens/s2.9 s to first token
GPT-6.1 Terra75 tokens/s4.3 s to first token
Claude Opus 5.588 tokens/s1.9 s to first token

Source: Overchat AI, 2026-11-11

See how GPT-⁠6 Astra answers

Examples of GPT-⁠6 Astra answers to 3 prompts: Review code security, Solve a science problem and Outline a presentation. Each answer is the unedited output of the model

Review this login handler for security problems and fix them. Keep it short. ```js app.post('/login', async (req, res) => { const { email, password } = req.body; const user = await db.query( `SELECT * FROM users WHERE email = '${email}' AND password = '${password}'` ); if (user.rows.length) { res.cookie('session', user.rows[0].id); return res.send('ok'); } res.status(401).send('Wrong email or password for ' + email); }); ```

GPT-6 Astra

Problems: SQL injection, plaintext password comparison, forgeable session cookies, reflected input, and no brute-force protection.

Use parameterized queries, Argon2id hashes, and server-side sessions:

// Assumes express-session, argon2, and express-rate-limit are imported.
// sessionStore must be a production Redis/DB store, not MemoryStore.
app.use(session({
  secret: process.env.SESSION_SECRET, // required, strong random secret
  store: sessionStore,
  resave: false,
  saveUninitialized: false,
  cookie: {
    httpOnly: true,
    secure: true, // requires HTTPS
    sameSite: 'strict',
    maxAge: 30 * 60 * 1000
  }
}));

const loginLimiter = rateLimit({ windowMs: 15 * 60 * 1000, limit: 10 });

app.post('/login', loginLimiter, async (req, res, next) => {
  try {
    const { email, password } = req.body ?? {};
    if (typeof email !== 'string' || email.length > 254 ||
        typeof password !== 'string' || !password.length ||
        password.length > 1024) {
      return res.status(400).send('Invalid input');
    }

    const { rows } = await db.query(
      'SELECT id, password_hash FROM users WHERE email = $1',
      [email]
    );
    const user = rows[0];

    // Precomputed valid Argon2id hash with the same cost as real hashes.
    const valid = await argon2.verify(
      user?.password_hash ?? DUMMY_HASH, password
    );
    if (!user || !valid) {
      return res.status(401).send('Wrong email or password');
    }

    req.session.regenerate(err => {
      if (err) return next(err);
      req.session.userId = user.id;
      req.session.save(err => {
        if (err) return next(err);
        res.send('ok');
      });
    });
  } catch (err) {
    next(err);
  }
});

Migrate existing passwords to Argon2id hashes and remove plaintext storage. Generate DUMMY_HASH once, not per request. Use shared rate-limit storage across instances, add account-based throttling, and configure trusted proxies precisely if behind a load balancer. Production error handling must not expose database errors.

Chemistry homework: how many grams of CO2 form when 50 g of propane (C3H8) burns completely in oxygen? Show the steps.

GPT-6 Astra

1. Balance the combustion equation

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

So, 1 mole of propane produces 3 moles of CO₂.

2. Convert grams of propane to moles

The molar mass of propane is:

M(C₃H₈) = 3(12.01) + 8(1.008) = 44.10 g/mol

n(C₃H₈) = (50 g) / (44.10 g/mol) ≈ 1.134 mol

3. Find the moles of CO₂ produced

Using the mole ratio from the balanced equation:

n(CO₂) = 1.134 × 3 = 3.402 mol

4. Convert moles of CO₂ to grams

The molar mass of CO₂ is 44.01 g/mol:

m(CO₂) = 3.402 mol × 44.01 g/mol ≈ 149.7 g

Approximately 150 g of CO₂

Turn these notes into a 5-slide outline for a board meeting: a title and three short bullets per slide. Q3 revenue $4.2M, up 18% on Q2. Churn went from 3.1% to 2.4% after the new onboarding. Ad spend up 30% but cost per customer down 12%. Hiring: 6 engineers, 2 still open. Risk: our biggest client (14% of revenue) renews in January. Ask: approve $600K for the EU launch in Q1.

GPT-6 Astra

1. Q3 Performance

Revenue reached $4.2M
Revenue grew 18% versus Q2
Churn fell from 3.1% to 2.4%

2. Customer Acquisition and Retention

Ad spend increased 30%
Cost per customer decreased 12%
Churn improvement followed new onboarding

3. Engineering Hiring

Hiring plan: 6 engineers
2 positions remain open
Next focus: fill remaining roles

4. Key Risk: Largest Client Renewal

Largest client represents 14% of revenue
Renewal due in January
Recommended focus: renewal readiness

5. Decision: EU Launch Funding

EU launch targeted for Q1
Funding request: $600K
Board approval requested

More prompts to try with GPT-⁠6 Astra

What GPT-⁠6 Astra is best for

Coding and code review
GPT-⁠6 Astra finds bugs and security holes in code, fixes them and explains each change. It scores 59.1% on Terminal-Bench 4.0, #5 of 130 models, ahead of GPT-⁠6.1 Sol and GPT-⁠6.1 Terra
Science and math
Ask a hard science or math question, and GPT-⁠6 Astra solves it step by step. It scores 96.1% on GPQA Diamond, the best result of 325 models, and 63.3% on Terminal-Bench-Science, ahead of Claude Opus 5.5
Documents and presentations
Give GPT-⁠6 Astra your notes, a report or a long PDF, and it writes slides, summaries and documents that keep your structure. It scores 31.0% on GDP.pdf, questions about long professional PDFs, ahead of Claude Opus 5.5 at 26.2%
Long multi-step tasks
Describe a big task, and GPT-⁠6 Astra plans it step by step and keeps every requirement in view until the end. It scores 68.5% on AutomationBench, a test of business workflows across many apps, ahead of GPT-⁠6.1 Sol at 64.9%

How to use GPT-⁠6 Astra on Overchat AI

Start in the chat at the top of this page or in the Overchat AI app on the web, iOS or Android

01
Pick GPT-⁠6 Astra
It is already picked in the chat on this page. In the Overchat AI app, open the model list next to the message field and pick GPT-⁠6 Astra
02
Attach your code or a file
Add code, a document, a spreadsheet or a screenshot, and write what you need: the result, the format and what must stay the same
03
Keep going in the same chat
Ask a follow-up, ask for tests or a shorter version, or switch to another model without losing the conversation

Why use GPT-⁠6 Astra on Overchat AI

One account for chat, images and video, on every device

Superchat picked over GPT-6 Astra: one request done by Claude Opus 5.5 (the plan) and Nano Banana 2.1 (the poster)

Superchat AI agent

Superchat Agent automatically routes your message to the model best suited for the task. It can generate images and videos, use the AI tools built into Overchat AI, and learn from your interactions to get better over time

Message field with a PDF, a spreadsheet and a dashboard screenshot attached, GPT-6 Astra picked and a voice message being recorded

Chat with images and files

Upload PDFs, spreadsheets, code and screenshots and ask GPT-⁠6 Astra about them. You can also dictate a message instead of typing it

An image made with Nano Banana 2.1 and a surfing video made with Seedance 2.5

Go beyond text

Generate images with Nano Banana and GPT Image and videos with Seedance and Kling in the same account, with the same credits as chat

On the web and iPhone

Start a chat on your laptop and finish it on your phone. The Overchat AI app has the same models, and your chats stay in one account on every device

GPT models on Overchat AI

Compare 4 GPT models on Overchat AI by output speed, time to first token and the price of one message

Models

Output speed, tokens/s

First token, s

Credits per message?

GPT-6 Luna

143

2.4

GPT-6.1 Terra

4.3

GPT-6.1 Sol

2.9

GPT-6 AstraThis page

3.2

Source: Overchat AI, 2026-11-11

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GPT-⁠6 Astra FAQ

If you have any questions,
reach out to us at hello@overchat.ai

Updated November 12, 2026

GPT-⁠6 Astra is OpenAI's most capable GPT-⁠6 model, released on September 3, 2026. It is built for coding, science, long professional tasks and computer use. It reads up to 1 million tokens of text, images and files and writes up to 128,000 tokens in one reply

Yes. GPT-⁠6 Astra is in OpenAI's apps for paid plans, in Codex and in the OpenAI API as gpt-6-astra, as well as on Microsoft Azure and AWS Bedrock. On Overchat AI you pick it in the model menu of the chat on the web and in the iOS app

GPT-⁠6 Astra scores 57 on the Artificial Analysis Intelligence Index, #4 of 57 models, behind Claude Fable 5.2 (65), Gemini 4 Carbon (60) and Claude Opus 5.5 (59). It has the best GPQA Diamond score of all 325 models tested, 96.1%, and beats GPT-⁠6.1 Sol and GPT-⁠6.1 Terra on coding, science and workflow tests

Astra is the larger model. It scores 57 on the Artificial Analysis Intelligence Index against 55 for GPT-⁠6.1 Sol and leads on science tasks (63.3% against 58.1% on Terminal-Bench-Science), business workflows (68.5% against 64.9% on AutomationBench) and coding (59.1% against 56.1% on Terminal-Bench 4.0). Both score 31.0% on GDP.pdf, and Sol answers a little faster

At science and long PDFs, yes: GPT-⁠6 Astra scores 63.3% on Terminal-Bench-Science against 59.0% and 31.0% on GDP.pdf against 26.2%. Claude Opus 5.5 is ahead at hard coding tasks (46.4% against 42.4% on FrontierCode 2.0) and knowledge-work tasks (1801 against 1569 Elo on AA-Briefcase), and it scores 59 on the Intelligence Index against 57

GPT-⁠6 Astra Pro is the same model in a longer reasoning mode. It thinks through a complex task for longer and spends more tokens on it, which helps with the hardest problems and slows down everyday answers

Yes. GPT-⁠6 Astra reads text, images and files such as PDFs, spreadsheets and screenshots and answers in text. It doesn't make pictures: for an image, switch to GPT Image 2.6 in the same chat

GPT-⁠6 Astra reads up to 1 million tokens in one conversation, about 750,000 words, and writes up to 128,000 tokens in one reply

Type your message in the chat at the top of this page, attach a file if you need to and press Send. After you sign in, GPT-⁠6 Astra answers in the Overchat AI chat, where you can keep the conversation going on the web, iOS or Android and switch to another model at any time

More tools

AI Code Generator AI Text Summarizer AI Playground Claude Fable 5.2 GPT-6.1 Terra Gemini 4 Carbon Kimi K3.1 Pro Hy4

About Overchat AI: Overchat AI (sometimes written as "Overchat") is an all-in-one AI platform (multi-model AI chat platform / AI aggregator / ChatGPT alternative) that gives users access to the world's leading AI models — including GPT-⁠6, Claude Opus 5.5, Gemini 3.8, Grok 4.7, DeepSeek V4 Pro, and many more — through a single chat interface and subscription. Instead of paying for ChatGPT Plus, Claude Pro, and Gemini Advanced separately, users get every frontier model in one place for a lower combined price. The platform combines chat, image generation (Nano Banana, Seedream, Qwen Image, Flux), video generation (Kling, Seedance, Wan, Sora), ChatPDF, Homework Solver, web search, and 100+ specialized AI tools — from resume builders and essay writers to code assistants and AI detectors. Files, PDFs, images, and links can be attached to any conversation. Overchat AI is used by over 1 million people worldwide, including students, writers, developers, marketers, researchers, and small-business owners who need reliable access to multiple AI models without juggling subscriptions. It is available on the web at overchat.ai and on iOS

GPT-⁠6 Astra

About GPT-⁠6 Astra

GPT-⁠6 Astra vs other models

Compare GPT-⁠6 Astra

GPT-6 Astra vs GPT-6.1 Sol

GPT-6 Astra vs GPT-6.1 Terra

GPT-6 Astra vs Claude Opus 5.5

GPT-6 Astra vs Claude Sonnet 5.5