Claude Fable 5 vs OpenAI o3
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Claude Fable 5
Anthropic · Jun 2026
The first GA model of Anthropic's Mythos class — a tier above Opus — and the current SWE-bench Verified leader, at $10/$50 per 1M tokens.
OpenAI o3
68.9OpenAI · Apr 2025
OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.
The verdict
Claude Fable 5 wins 1 of the 1 benchmarks these models share, against 0 for OpenAI o3. On price the gap is dramatic: OpenAI o3 works out roughly 5.7x cheaper per blended million tokens. Claude Fable 5 also takes 1M of context versus 200K for OpenAI o3.
Benchmark head-to-head 1–0
Specs & pricing
| Claude Fable 5 | OpenAI o3 | |
|---|---|---|
| modhub Index | — | 68.9 |
| Input price / 1M | $10 | $2 |
| Output price / 1M | $50 | $8 |
| Context window | 1M | 200K |
| Max output | 128K | 100K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Jan 2026 | May 2024 |
| Released | Jun 2026 | Apr 2025 |
| Example monthly cost* | $175.00 | $32.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Claude Fable 5 or OpenAI o3?
- Claude Fable 5 wins 1 of the 1 benchmarks these models share, against 0 for OpenAI o3. On price the gap is dramatic: OpenAI o3 works out roughly 5.7x cheaper per blended million tokens. Claude Fable 5 also takes 1M of context versus 200K for OpenAI o3.
- Which is cheaper, Claude Fable 5 or OpenAI o3?
- Claude Fable 5 costs $10/$50 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $175.00 versus $32.00.
- Which model is better for coding, Claude Fable 5 or OpenAI o3?
- On SWE-bench Verified — the standard agentic-coding benchmark — Claude Fable 5 scores ~95% versus 69.1% for OpenAI o3, making Claude Fable 5 the stronger pick for coding agents.