Feature · Fable 5.2

Anthropic says "start with Opus," so where is Fable 5.2 actually worth the switch?

"It's been under an hour and I'm already struggling with 'should I use Opus 5.5 or Fable 5.2?'" Developer Theo's post drew about 2,400 likes. On Nov. 9 Anthropic released a cheaper, faster Fable 5.2 while still recommending Opus 5.5 for most work. We checked the benchmarks and cost curves in Anthropic's announcement and what developers are saying.

1. Price down 20%, speed up 30%

   Anthropic priced Fable 5.2 at $8 per million input tokens and $40 per million output tokens, 20% below Fable 5.1 ($10 and $50). Output is up to 30% faster than 5.1, and an optional fast mode that speeds generation up to 2.5x costs $16 and $80. Fable and Mythos are the same underlying model; Fable is the version with cyber and biology safeguards.

2. Coding: Opus-level at half the cost, top score at max effort

   FrontierCode 2.0 measures whether a model's code changes would be merged by open-source maintainers. At High effort Fable 5.2 scored 45.3%, about level with Opus 5.5's best (45.5%) at roughly half the cost per task, and ahead of GPT-6 Astra's best (42.8%) at about the same cost. At Xhigh it reached 49.1%, the highest of any released model Anthropic tested. All figures are Anthropic's.

3. The hidden variable is effort

   Anthropic says that at Medium effort, the default in Claude apps and Claude Code, Fable 5.2 handles hard tasks with fewer tokens than Fable 5.1. Cursor likewise advised starting at the default rather than carrying over old settings, since effort levels behave differently. On CursorBench Fable 5.2 scores 60% at max effort and 56.9% at default, versus 49.2% for Fable 5.1.

4. Big gap in hardware design, not ahead on chart reading

   On BenchCAD 2.1, a hardware engineering test, Fable 5.2 scored 83.5 at max effort, well ahead of Opus 5.5 (65.3) and Fable 5.1 (44.4). On chart reading, Fable 5.2 at Medium effort scored 66.4%, above Opus 5.5 at max (64.4%) but below GPT-6 Astra (71.0% at max) and Gemini 4 Carbon (72.5%) shown on the same chart. It does not win every column.

5. Some problems are cheap to solve

   On the expert-level HLE test, Fable 5.2 at Low effort matched Opus 5.5's top score for less than one-tenth of the cost per task. On Perplexity's WANDR data-collection benchmark, Medium effort matched Opus 5.5's top score at about 40% of the cost. The HLE chart also shows GPT-6 Astra (Max) at 57.2%.

6. Positive에단 몰릭 · X (Ethan Mollick) ↗

   Praise: "a sort of Jagged AGI"

   Wharton professor Ethan Mollick had Fable 5.2 launch a business, do academic research, hack hardware and build 3D models, and said it "crosses the line into being a sort of Jagged AGI." Greg Isenberg pointed to the jump in real freelance work completed from 21% to 41% and predicted agencies will charge per deliverable instead of per hour. That reading is his own opinion.

7. Mixed펠릭스 리제베르그 · X (Felix Rieseberg) ↗

   Mixed: even Anthropic staff say Opus for daily work

   Felix Rieseberg wrote that Fable beats Opus on big, long tasks but "I often still prefer Opus 5.5 for everyday work. Fable's got a big brain and thinks a little slower." Theo said he was struggling within an hour of launch over which to use. One reply summed it up: Opus if price matters, Fable if your API is unlimited.

8. Negative엘리 바쿠크 외 · X (Boris Cherny) ↗

   Limits: usage caps and access

   A reply to an Anthropic engineer's game demo said it is easy to go AAA "when you're not on the same weekly limit as the rest of us," and elie speculated that Anthropic may not publicly release a model better than Opus 5.5 at LLM training in the coming months (about 250 likes). Anthropic has not confirmed that. As Boris Cherny said, usage resets depend on subscription length: one for Pro, up to three for Max, Ultra and Team Premium.