Claude Fable 5.1 vs o3
Benchmark Performance
Available Benchmarks
Technical Differences
Side-by-Side Facts
| Field | Claude Fable 5.1 | o3 |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Family | Claude 5 1 | O3 |
| Model | Claude Fable 5.1 | o3 |
| Version | Claude Fable 5.1 | o3 |
| Lifecycle | active | active |
| Released | 2026-09-01 | 2025-04-16 |
| Knowledge cutoff | 2026-06-01 | 2024-06-01 |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,000K | 200K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Anthropic (Standard) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
15 comparable fields · 9 material differences · Pair passes the primary-source comparison gate
Claude Fable 5.1 Capabilities
o3 Capabilities
Internal Comparison Graph
Related Comparisons
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|---|---|---|---|
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Claude Fable 5.1Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
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Claude Fable 5.1Anthropic | vs |  Kimi-K3Moonshot AI | cross-developer peersimage, text |
 MiniMax-M3MiniMax | vs | Claude Fable 5.1Anthropic | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Claude Fable 5.1Anthropic | vs |  Hy4 previewTencent | cross-developer peerstext |
Claude Fable 5.1Anthropic | vs | Seed 2.1 ProByteDance Seed | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs |  Mistral Large 3Mistral AI | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Fable 5.1 vs o3 FAQs
Is Claude Fable 5.1 or o3 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Fable 5.1 and o3, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Fable 5.1 or o3?+
Claude Fable 5.1 is $10.00 and o3 is $1.00 per million tokens, so o3 is cheaper on this metric. Claude Fable 5.1 is $50.00 and o3 is $4.00 per million tokens, so o3 is cheaper on this metric.
Which has a larger context window, Claude Fable 5.1 or o3?+
Claude Fable 5.1 has the larger sourced context window. Claude Fable 5.1 supports 1,000K and o3 supports 200K.
Which performs better in benchmarks, Claude Fable 5.1 or o3?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can Claude Fable 5.1 or o3 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Fable 5.1 is not marked open weight; o3 is not marked open weight.
Can Claude Fable 5.1 and o3 understand images?+
Claude Fable 5.1 is documented with image input; o3 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Fable 5.1 or o3?+
Claude Fable 5.1 has the larger sourced maximum output: Claude Fable 5.1 supports 128K and o3 supports 100K output tokens.
Do Claude Fable 5.1 and o3 support reasoning and tool use?+
Claude Fable 5.1: reasoning, tool calling, and image input. o3: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Fable 5.1 or o3?+
Claude Fable 5.1 has 1 sourced provider route; o3 has 2, so o3 has broader tracked availability.
Which offers better value, Claude Fable 5.1 or o3?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.