GPT Astra
OpenAI's top-tier GPT-6 model, used through ChatGPT/Codex subscription plans and the API.
Liked for coding, planning and design review,1234 and for math proofs and CAD or 3D modeling work.5678 The most common complaint is that it burns through usage limits fast,910111213 followed by odd code style and reports of quality degrading.14151617
Why people recommend it
Coding quality · 3
Several commenters rank it near the top for coding, and some found it better than rival models.
“My experience with Astra (I use it at home writing Go and C) for coding has been fantastic.”
“Both Astra and 6.1-Sol are pretty comfortably ahead of Opus 5.5”
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Planning and review · 3
Often reserved for specs, high-level design, planning and code review in multi-model setups.
“Very tricky stuff, like planning a new feature, design review, or code review of a complex change across multiple repositories is where I leverage Astra.”
“I use Astra for destroying vaguely scoped asks and tasks, and then for high-level design and plan generations”
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“burns half of day sub of astra for 200 USD. runs 1 hour on our repo.”
CAD and 3D · 3
Reported to work well for CAD, 3D modeling and design plans through tools like FreeCAD, build123d and Blender MCP.
“Astra in Codex CLI is good with FreeCAD if you let it use the FreeCAD Python runtime in a headless session.”
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“I used blender mcp and Astra to do a woodworking design a few days ago, plans came out great.”
Math and research · 3
Commenters report using it to produce new mathematical proofs and for knowledge work where accuracy matters.
“I used OpenAI Dots running GPT-6 Astra on the Ultra reasoning mode”
“I used Fable 5.1 and Astra to solve and prove a long-standing mathematical problem”
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“Astra on Extra High. Knowledge work, the right answer is much more important than a fast or cheap answer.”
Instruction following · 2
Commenters say it follows AGENTS.md instructions closely and does not cheat, for example by deleting failing tests.
“Sol and Astra are by far the best of the models I use at following the instructions in AGENTS.md”
“I use Astra/Sol for coding, and I haven't run into any issues with them trying to hack someone or break the law”
Concise output · 1
One former Claude user found its answers more concise and information-dense while being similarly accurate.
“Astra’s outputs are much more concise while being similarly accurate, they seem more information dense.”
Caveats and dissent
Usage limits · 3
Many say it exhausts weekly or subscription usage very quickly, and some call it too expensive.
“tried Astra and it also burned though my weekly usage in a day, with a _single_ agent.”
“I used Astra, and it lasted less than hour before it was dead for a month”
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“Astra blows through usage limits too fast to be a daily driver and writes weird code”
Code style · 3
Commenters report odd code such as missing blank lines, overly complex functions, and poor architectural choices.
“The last time I used astra it wrote a lot of rust code where it would insert almost no empty lines at all.”
“Astra also creates things like “report” functions with 10 arguments”
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Perceived degradation · 3
Some users believe it was silently downgraded or became worse after launch.
“Even Astra has been noticeably degraded for me and everyone else I have asked.”
“Many empirical examples of Astra silently downgrading the models.”
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“With Astra and Fable I am no longer able to finish tasks I used to be able to do and I revert to older models.”
Fails hard tasks · 3
Commenters report failures on a large port, PCB schematics, and test suites that missed bugs.
“never got past like 84% compat.”
“Those models were not capable of even schematic editing or building.”
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“64 of the bugs that abloh planted had passed Astra's test suite”
Slow, rabbit-holes · 2
Some found it very slow on high reasoning settings and prone to chasing minor implementation details.
“I'm not going to keep using Astra unless I can get some benefit from it”
“Whereas Sol and Astra kept rabbit holing and looking for tiny implementation errors.”
Often compared with
2 moved from GPT Sol to GPT Astra
2 moved from GPT Astra to GPT Sol
1 moved from Claude Opus to GPT Astra
1 moved from GPT Astra to Claude Opus
2 moved from Claude Fable to GPT Astra
1 moved from GPT Astra to Claude Fable
1 moved from Claude Code to GPT Astra
2 moved from Claude to GPT AstraGPT Terra9 comments mention both
Who recommends it in their own words
From the makers not counted in the ranking
“All built in, including autoguiding and autofocusing.”
Threads where it came up
- Ask HN: What default model do you use and why? 11 mentions
- GPT-5.6 Luna vs. GPT-6 Astra: Is a $1.20 Model Good Enough for Code Review? 8 mentions
- GPT-6 Sol and Luna 6 mentions
- GPT 6.1 Sol: Near-Astra intelligence for a fifth of the price 4 mentions
- SlopCodeBench 10/2026 – Opus 5.5, Astra wins overall, xhigh considered harmful 3 mentions
- Why isn't the industry freaking out about DeepSeek 4.1 Flash? 3 mentions
Also written as GPT-6 Astra, GPT Astra, Astra 6, GPT 6 Astra. Data: gpt-astra.json. Quotes are verbatim; the verdict and theme labels are written by a model from these comments, and every clause links to its sources.
All comments 49
“I don’t think it measures up to Fable 5.1 or Astra”
“I use Astra 6 Extra High for everything.”
“Also should work in as pair of Astra + Luna in CodeX.”
“Astra is really not relevant for the average dev except to do some moonshot task”
“when they're not I use Astra or Opus 5.5”
“Opus and Astra take them handily.”
“2. Astra”
“Sol and Astra are by far the best of the models I use at following the instructions in AGENTS.md”
“Astra also creates things like “report” functions with 10 arguments”
“The last time I used astra it wrote a lot of rust code where it would insert almost no empty lines at all.”
“"End-User Customer Advocate" -> Astra, plan mode.”
“Astra verified the results”
“Astra in Codex CLI is good with FreeCAD if you let it use the FreeCAD Python runtime in a headless session.”
“I used blender mcp and Astra to do a woodworking design a few days ago, plans came out great.”
“the latest models -- Opus 5.5, Astra, etc. juggle multiple tasks, delegate exceptionally well and are very good at working independently.”
“Very tricky stuff, like planning a new feature, design review, or code review of a complex change across multiple repositories is where I leverage Astra.”
“I too find that Opus5.5/Astra/6 are better for UI/UX now”
“Previously I planned with Opus/Sol/Astra”
“never got past like 84% compat.”
“The code itself is written almost exclusively by Astra 6.”
“Astra is current a bit better than Opus 5.5.”
“I used OpenAI Dots running GPT-6 Astra on the Ultra reasoning mode”
“Initial motivation were success stories of GPT Astra in creating 3d worlds so we decided to give it a try.”
“I can compare what I use at home vs paid models like astra at work and the difference is mostly meaningless.”
“Astra can solve problems that Sol can't but for some reason on easy stuff makes uglier solutions.”
“while I testdrive Astra”
“If a commit was written with Fable/Opus, I use Sol/Astra to write a well reasoned commit message.”
“I used Astra to help me build an immersive VR experience”
“Both Astra and 6.1-Sol are pretty comfortably ahead of Opus 5.5”
“I use Astra xhigh, sometimes max, never ran out of tokens on the 100$ thing.”
“so I switched to Astra which is awesome”
“I'm not going to keep using Astra unless I can get some benefit from it”
“Astra is a pretty good model”
“then switched to 2 openai for astra”
“My experience with Astra (I use it at home writing Go and C) for coding has been fantastic.”
“Astra being a bit of a "over-correct over-validation nit-picker"”
“tried Astra and it also burned though my weekly usage in a day, with a _single_ agent.”
“I asked Astra to come up with a plan for Playwright testing the whole App”
“astra designed the project and wrote spec.md”
“I used Astra, and it lasted less than hour before it was dead for a month”
“Even Astra has been noticeably degraded for me and everyone else I have asked.”
“I used Fable 5.1 and Astra to solve and prove a long-standing mathematical problem”
“I use Astra for rapidly consuming my token limit on a task that would not consume it on 5.6 Sol.”
“I use Astra for destroying vaguely scoped asks and tasks, and then for high-level design and plan generations”
“Astra blows through usage limits too fast to be a daily driver and writes weird code”
“Astra is extremely RL fried, and nobody is talking about it.”
“astra does tend to chew up usage”
“Astra xhigh - for specs, analysis.”
“With Astra and Fable I am no longer able to finish tasks I used to be able to do and I revert to older models.”