Standard Compute
Model comparison 2026

Claude Fable 5.1 vs Claude Haiku 4.5

Claude Fable 5.1
Anthropic · Frontier · Proprietary
$22/1M · 1M ctx
Claude Haiku 4.5
Anthropic · Budget · Proprietary
$2.20/1M · 200K ctx

Community vote

Pick a winner in each dimension. You can change your vote any time.

Output Quality
Correctness and depth of what it produces
Agentic Ability
Tool calls, instruction-following, and multi-step tasks
Speed
Tokens per second and time-to-first-token
Value for money
How much capability you get per dollar
Reliability
Consistent results: fewer refusals, loops and format breaks

Specs and pricing side by side

Spec
Fable 5.1
Haiku 4.5
Maker
Anthropic
Anthropic
Blended price / 1M
$22
$2.20
Input / output
$10 in · $50 out / 1M tokens
$1.00 in · $5.00 out / 1M tokens
Context window
1M
200K
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.7
8.2
Agentic Ability
9.7
8.2
Speed
6.7
9.0
Value for money
6.9
8.3
Reliability
9.6
9.3

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: Fable 5.1 or Haiku 4.5?

Updated 2026-10-13

Choose Claude Fable 5.1 if you want teams already standardized on Fable that want the newest premium Claude. Choose Claude Haiku 4.5 if you want cheap, fast subtasks and subagents inside a larger workflow.

In our editorial scoring, Claude Fable 5.1 leads in 3 of five dimensions (output quality, agentic ability and reliability), while Claude Haiku 4.5 leads in 2. On price, Claude Fable 5.1 runs about $22 per 1M tokens (blended) and is proprietary; Claude Haiku 4.5 is about $2.20 and proprietary.

Where Fable 5.1 falls short
  • Opus 5.5 scores higher on Artificial Analysis and Terminal-Bench 4.0 at less than half the price
  • Slow: about 67 output tokens/s at max effort
Full Fable 5.1 breakdown →
Where Haiku 4.5 falls short
  • Quality well below Sonnet/Opus on hard tasks
  • 200K context, not 1M
Full Haiku 4.5 breakdown →

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