model comparison

vs

Claude Fable 5.2 vs Claude Fable 5.1

two Anthropic models, compared on listed price, real workload cost, context and capabilities.

the short answer

  • on Humanity's Last Exam (with tools), as each maker reports it, Claude Fable 5.2 scores 74.2% and Claude Fable 5.1 65.0%.
  • Claude Fable 5.2 lists lower input and output prices.
  • Claude Fable 5.2 reads cached input for less ($0.2/M against Claude Fable 5.1's $0.25/M), which decides the bill for agents that resend long context.

side-by-side specs

specClaude Fable 5.2Claude Fable 5.1
providerAnthropicAnthropic
input price$8/M$10/M
output price$40/M$50/M
cached input$0.2/M$0.25/M
blended price (3:1)$16/M$20/M
context window1M tokens1M tokens
max output128k tokens128k tokens
inputtext, imagestext, images
structured outputyesyes
weightsclosedclosed
releasedNovember 9, 2026September 1, 2026
availabilityliveretires 17 November 2026
Humanity's Last Exam (with tools) (maker-reported)74.2%65.0%

same work, both models

workloadClaude Fable 5.2Claude Fable 5.1
one chat reply3,000 tokens in, 500 outClaude Fable 5.1 costs 1.3× as much as Claude Fable 5.2$0.04$0.06
summarise a 100-page report50,000 tokens in, 1,500 out, one requestClaude Fable 5.1 costs 1.2× as much as Claude Fable 5.2$0.46$0.58
1,000 classification calls500 tokens in, 20 out, per callClaude Fable 5.1 costs 1.3× as much as Claude Fable 5.2$4.80$6.00
coding-agent session2M tokens in across ~60 turns, 60,000 out, no cache$18.40$23.00
same session, cached85% of input read from the prompt cache, the rest written to it$5.74$7.18

at listed rates. token counts are typical sizes, not measurements.

Claude Fable 5.2 pricing notes

  • cache hits bill at $0.20 per 1M tokens (0.025x input); cache writes at $10 (5-minute tier) or $16 (1-hour tier).
  • the full 1M-token window bills at the standard rate, with no long-context surcharge.
  • adaptive thinking is always on and cannot be disabled; the effort setting (default high) steers its depth.

Claude Fable 5.1 pricing notes

  • cache hits bill at $0.25 per 1M tokens (0.025x input), a quarter of Fable 5's $1; cache writes at $12.50 (5-minute tier).
  • the full 1M-token window bills at the standard rate, with no long-context surcharge.
  • adaptive thinking is always on and cannot be disabled; the effort setting (default high) steers its depth.

when to pick which

Claude Fable 5.2

Anthropic's Claude model for demanding reasoning and long-horizon agentic work, released as the successor to Fable 5.1. It costs less than 5.1 on input, output and cache, at the same context window; Anthropic points most workloads to the cheaper Opus 5.5.

pick it if

  • Opus 5.5 at higher effort still falls short on your evals
  • you run Fable 5.1 today and want lower rates on the same window
  • you run long agent sessions; cache hits bill at 2.5% of input

skip it if

  • Opus 5.5 covers your workload at half the per-token price
  • your code forces tool use, prefills replies, sets temperature or edits earlier turns; all return errors

Claude Fable 5.1

Anthropic's Claude model for demanding reasoning and long-horizon agentic work, released as the successor to Fable 5. Claude Fable 5.2 replaces it and costs less on every rate.

pick it if

  • your integration is pinned to 5.1 while you test Fable 5.2
  • you run long agent sessions; cache hits bill at 2.5% of input

skip it if

  • you are starting new work; Claude Fable 5.2 costs less on every rate at the same window
  • your code forces tool use, prefills replies or sets temperature; all return errors

faq

which is better, Claude Fable 5.2 or Claude Fable 5.1?

on Humanity's Last Exam (with tools), as each maker reports it, Claude Fable 5.2 scores 74.2% and Claude Fable 5.1 65.0%. these are each maker's own numbers, not a controlled head-to-head; the spec table lists every benchmark both publish.

which is cheaper, Claude Fable 5.2 or Claude Fable 5.1?

Claude Fable 5.2 lists lower input and output prices. on a coding-agent session (2M tokens in, 60,000 out) Claude Fable 5.2 costs $18.40 and Claude Fable 5.1 $23.00.

can i switch between Claude Fable 5.2 and Claude Fable 5.1 mid-task?

yes. in an octomind session, /model octohub:claude-fable-5-2 and /model octohub:claude-fable-5-1 switch models without losing the conversation, so you can draft on one and review on the other.

try either model

switch between models inside the same octomind session.

open the panel all models

prices from the catalog of 2026-11-10