The GPT 6 Astra Vs Claude Fable 5.1 Debate Is Finally Over

GPT 6 Astra vs Fable 5.1: we tested Claude Fable 5.1 against OpenAI Astra on real client work. Sponsored by Zapier! Zapier SDK levels you up, letting you build custom, code-based automations directly in your editor. Start building with Zapier SDK today: https://bit.ly/4xsGyPW Community with All Resources: https://ailabspro.io/?v=BwNNcob3-A0 The Roundup: Our daily newsletter covering the AI stories. Join now: https://www.theroundup.so/ How We Tested GPT 6 Astra vs Fable 5.1 - The biggest AI news of the month: Anthropic released Fable 5.1 on September 1 and OpenAI dropped GPT-6 Astra a few days later. - Astra scored almost 100% on the ARC-AGI test, and both posted very high benchmark numbers. - We are a software company, so we handed both models real client work instead of trusting benchmark numbers. - GPT 5.6 judged the results and never knew which came from Claude Fable and which came from Astra. - Final scores: Astra 86 out of 100, Fable 84. The overall winner did not win every category. Quality: Claude Fable 5.1 vs GPT 6 Astra - Code structure and organisation: Fable 90, Astra 78, and Fable led on this across every project. - Amount of requested work finished: Fable 91, Astra 84, because Fable also fixed problems we never asked about. - Features that worked without follow-up fixes: Astra 87, Fable 85, since Astra checked its apps more thoroughly. - Experience of using the app: Astra 89, Fable 88. Overall quality goes to Fable at 88 against 84. Long-Running Tasks: Fable vs Astra - Each model got an app idea worded to its own prompting guide, with no specific details supplied. - Astra worked about 32 minutes, Fable about 44, and neither stopped early or asked us what to do next. - Astra's app had a side panel that would not scroll far enough to reach sign-out. - Fable's app worked but packed everything together, with repeated gradients and that familiar AI generated look. - Score: Astra 93, Fable 90. Design and Ease of Use - We built a viewer for each model's results so we could judge the designs ourselves instead of trusting a score. - Four tasks: a font store landing page, a horror game page, a music festival site and a parallel parking game. - Interaction score: Fable 94, Astra 85, thanks to its animations and interactive elements. - Codex has a built-in image generation tool, and Astra used it for artwork while Fable drew its own as SVGs. - On gpt astra 6 vs fable 5.1 for design, Astra won spacing, contrast and readability while Fable won animation and interactivity. Cost, Speed and Tool Calls - We ran on our normal subscriptions, so the costs are estimates of API pricing based on tokens used. - Total estimated cost: Fable $49.18, Astra $27.69 including helper agents, which is about 44% lower. - Across four design tasks Fable produced nearly three times the output tokens, and its prompting guide notes it writes more. - Tool calls from the main agent across six runs: Fable 443, Astra 287. - Cost score: Astra 80, Fable 66. Speed score: Astra 70, Fable 67, at 62 minutes against 73. Instruction Following and Review Quality - In Claude Code, Fable added a co-authored credit we had explicitly banned and created two files by running commands instead of using the file editing tools we required. - Instruction following: Astra 96, Fable 88. - On identical code with four planted bugs, Fable found all four plus five confirmed extras, while Astra found two and still called the review complete. - Neither model invented bugs in the three parts that looked suspicious but were correct. - On a larger project with nine confirmed problems, Astra fixed five and Fable fixed four. Review score: Astra 84, Fable 78. Pricing, Plans and Context Limits - Both cost $10 per million input tokens and $50 per million output tokens, but Anthropic Fable 5.1 cut the price of cached reads by 75%. - Claude Fable 5 models have been in Claude Code for a while, yet 5.1 is not in the Claude Pro plan and needs usage credits. - Max plans include it, though Fable models carry lower limits than the rest. - Astra OpenAI is not treated as a separate model, so it runs on the normal Codex limits in ChatGPT Plus and Pro. - Context: a million tokens for Fable in Claude Code, while Codex defaults GPT Astra to 272,000 even though its API allows more. Safety Rules and Model Switching - Both labs added guardrails, and each model reacts differently when your request trips one. - GPT-6 refuses the task outright and tells you. - Claude AI switches Claude Code from Fable to a weaker model, and many people found it had happened without them knowing. 0:00 Intro 1:07 The Models 3:58 Quality 5:27 Sponsor 6:23 Long Tasks 8:14 Design 11:14 Efficiency 12:32 Instructions 13:11 Review 14:22 Verdict #ai #Claude #GPT6Astra #ClaudeCode #ChatGPT #Astra #Fable51 #GPT6AstraVsFable51