Claude Sonnet 5 vs Fable 5 (2026): Price, Specs & Which to Use
Claude Sonnet 5 vs Fable 5 compared: $2/$10 vs $10/$50 pricing, 1M context, benchmarks, and exactly when to pick the cheaper Sonnet 5 over the Mythos-class Fable 5.
Fable5 EditorialAnthropic shipped two big changes in 48 hours: Claude Sonnet 5 launched June 30, 2026, and Claude Fable 5 returned globally on July 1 after its export-control suspension. If you're deciding between them, here's the side-by-side.
Claude Sonnet 5 vs Fable 5: the table
| Dimension | Claude Sonnet 5 | Claude Fable 5 |
|---|---|---|
| Tier | Mid-tier, most agentic Sonnet | Mythos-class, priced a tier above Opus |
| API model ID | claude-sonnet-5 | claude-fable-5 |
| Intro price (in / out per M) | $2 / $10 (through Aug 31) | $10 / $50 |
| Standard price | $3 / $15 | $10 / $50 |
| Context window | 1M tokens | 1M tokens |
| Max output | 128K tokens | 128K tokens |
| Availability | All plans (default Free/Pro) | Pro, Max, Team, select Enterprise |
| Best for | High-volume coding, tool use, agents | Hardest reasoning, multi-day autonomy |
Price: the 5x gap
At introductory rates, Sonnet 5 is roughly five times cheaper than Fable 5 on both input and output — $2/$10 vs $10/$50. Even after Sonnet 5's intro window closes on August 31, 2026 ($3/$15), it stays well under half of Fable 5's price.
One caveat: Sonnet 5 uses a new tokenizer that counts ~30% more tokens for the same text, so the effective gap is a bit smaller than the sticker price suggests — but Sonnet 5 is still dramatically cheaper. See the full breakdown on the Sonnet 5 page and the Fable 5 page.
Which one should you use?
Use Sonnet 5 when:
- You're doing high-volume coding, refactors, or tool/browser/terminal agent work
- Cost matters and "close to Opus 4.8" quality is enough
- You want the default, fastest option in Claude Code, Cursor, or Copilot
Use Fable 5 when:
- The task is the hardest tier — large multi-day refactors, expert analysis, one-shot correctness
- Peak reasoning quality justifies paying 5x
- You need Mythos-class capability beyond what Opus can do
A practical note: some routine Fable 5 coding and debugging requests currently fall back to Opus 4.8 while Anthropic tunes its new safety classifiers — so for a lot of everyday work, Sonnet 5 is both cheaper and effectively comparable.
Availability status (July 1, 2026)
- Sonnet 5 — live everywhere since June 30: Claude apps, Claude Code, API, AWS Bedrock, Google Vertex, Microsoft Foundry, Cursor, VS Code, GitHub Copilot, OpenRouter.
- Fable 5 — back as of July 1: API, Claude apps (Pro/Max/Team/select Enterprise), AWS, Google Cloud, Microsoft Foundry, GitHub Copilot, OpenRouter.
Bottom line
Start on Sonnet 5 — it's five times cheaper and handles most agentic coding at close to Opus quality. Escalate to Fable 5 for the hardest, highest-stakes work. Keep one portable system prompt so switching between them costs nothing.
Independent analysis, last updated July 1, 2026. Official sources win on conflict — see anthropic.com/news.