GPT-5.4 vs Claude Fable 5.1
Compare GPT-5.4 and Claude Fable 5.1 side-by-side. See comparisons of price, response speed, accuracy, and file support to choose the best model for your task.
Overview
GPT-5.4 vs Claude Fable 5.1 Overview
Everything you need to know about these AI models, including capabilities, performance, pricing, and technical details.
OpenAI / GPT-5.4
maxDescription
OpenAI describes GPT-5.4 as its more affordable model for coding and professional work. It carries OpenAI's top reasoning rating, a million-token context window, and web search. The trade is speed and freshness: it runs at medium speed and its knowledge stops in August 2025. Strong value when the work is hard but not urgent.
Anthropic / Claude Fable 5.1
maxDescription
Anthropic's most capable generally available model, sitting above the Opus line. Fable 5.1 is built for long, unsupervised work: multi-day coding, agentic research, and tasks that run across dozens of tool calls. It reads text and images, maintains a very large context, and reasons before every answer at an adjustable depth. Its knowledge is the most recent of any Claude model. Anthropic positions Opus 5 as the starting point for most work, and Fable 5.1 for teams whose evaluations demand a higher ceiling.
About
About
Capabilities
Capabilities
Comparison
Why Use GPT-5.4 and Claude Fable 5.1?
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OpenAI / GPT-5.4
maxAffordable Frontier Coding
OpenAI positions this squarely as its cheaper route into complex coding and professional work. Handles large codebases and multi-step engineering tasks with reasoning effort you can push from none up to xhigh when a problem demands it.
Better Reasoning at Lower Price
OpenAI rates its reasoning Highest, the top of the company's own scale, at half the price of its newest frontier model. Reasoning tokens are supported, and effort defaults to none, so you decide when the model thinks hard.
One Million Context Tokens
A 1,050,000-token context window. Load a full codebase, a research corpus, or a large document set and work across all of it in one session. Prompts above 272,000 input tokens are billed at a higher rate.
Extended Professional Writing
Writes up to 128,000 tokens in a single response, enough for long reports, complete documentation sets, and extended technical writing without breaking the job into parts.
Web Search Support
Web search is a supported tool, so it can ground answers in live sources. Its knowledge cutoff is 31 August 2025, which is older than most frontier models, so recent events genuinely need that search rather than merely benefiting from it.
Reads Text and Images
Text and image input, text output. OpenAI's documentation states plainly that audio and video are not supported. File search is supported, so it can work across uploaded documents.
Anthropic / Claude Fable 5.1
maxLong-Running Coding
Anthropic's strongest model for multi-day coding sessions and codebase research. Built to sustain complex software engineering across many steps and tool calls without a human checking in at each one.
Adaptive Thinking Always On
Reasoning is always on, with adjustable effort rather than an on-off switch. Steer depth up for the hardest problems or down for lighter work, without restructuring the prompt each time.
Room For Whole Projects
A very large context window, among the largest available. Load an entire codebase, a long research corpus, or a large document set and work across all of it in a single session.
Document-Heavy Analysis
Built for document-heavy analysis and multi-step automation alongside coding. Suited to work that reads across large, mixed source material and produces structured, reviewable output.
Long-Horizon Agent Work
Its defining strength. Retains context, uses tools, evaluates results, and works on a task through many steps. Built for agents who run for a long time with little supervision.
Text And Image Input
Reads text and images in the same prompt, so you can send screenshots, diagrams, or scanned pages alongside your question. Output is text only. Audio and video are not accepted.
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Why chat with GPT-5.4 and Claude Fable 5.1 on Aymo AI?
Aymo gives you more than access to GPT-5.4 and Claude Fable 5.1—it provides a complete multi-model AI workspace designed for productivity.
Compare Responses
See how GPT-5.4 and Claude Fable 5.1 performs alongside Claude, Gemini, Grok, and other leading AI models.
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Upload Once
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