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Head-to-head comparison

Claude Fable 5.1 vs Qwen3.8 Flash

Claude Fable 5.1 (Anthropic) and Qwen3.8 Flash (Qwen) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 3 September 2026

As of 3 September 2026, Claude Fable 5.1 holds the stronger ModelCap Index position (#2 vs #17); and Qwen3.8 Flash is 106.4× cheaper per output token ($0.47/1M vs $50.00/1M).

Which should you choose?

Choose Claude Fable 5.1 if…

  • you want the stronger overall ModelCap Index position — #2 against #17 (84.1 vs 72.1 points).
  • you want provider choice — 4 listed API providers against 1.
  • AA Intelligence Index is your yardstick — 65.7 against 55.8.
  • AA Terminal-Bench 2.1 is your yardstick — 91.4% against 86.1%.
  • AA Humanity's Last Exam is your yardstick — 59.1% against 38.0%.
  • you want the more recently listed model — Claude Fable 5.1 was listed 1 September 2026, Qwen3.8 Flash 26 August 2026.

Choose Qwen3.8 Flash if…

  • API cost matters — $0.47/1M output tokens against $50.00/1M, about 106.4× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.15/1M against $10.00/1M.

Claude Fable 5.1 vs Qwen3.8 Flash: specs, pricing and context

Specification comparison of Claude Fable 5.1 and Qwen3.8 Flash
FieldClaude Fable 5.1AnthropicQwen3.8 FlashQwen
ModelCap Index position#2#17
Index score84.172.1
EvidenceMeasuredMeasured
Input price / 1M tokens$10.00$0.15
Output price / 1M tokens$50.00$0.47
Context window1M tokens1M tokens
Max output tokens128K131K
API providers listed41
Weight accessAPI onlyRestricted license
Input modalitiesText, Image, FileText, Image, Video
First listed1 September 202626 August 2026
PublisherAnthropicQwen

Evidence: 2 public benchmark observations across 2 boards · 1 public benchmark observation across 1 board. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Claude Fable 5.1 vs Qwen3.8 Flash

Public benchmark boards where Claude Fable 5.1 or Qwen3.8 Flash has a published result
BoardClaude Fable 5.1Qwen3.8 FlashLeads
ARC-AGI-2ARC Prize Foundation90.0%Max—Only one result
AA Intelligence IndexArtificial Analysis65.7intelligence-index55.8intelligence-indexClaude Fable 5.1
AA Terminal-Bench 2.1Artificial Analysis91.4%terminal-bench-2.186.1%terminal-bench-2.1Claude Fable 5.1
AA Humanity's Last ExamArtificial Analysis59.1%humanitys-last-exam38.0%humanitys-last-examClaude Fable 5.1

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Claude Fable 5.1 vs Qwen3.8 Flash: common questions

Is Claude Fable 5.1 better than Qwen3.8 Flash?

Claude Fable 5.1 ranks higher on the ModelCap Index as of 3 September 2026: #2 against #17. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is Claude Fable 5.1 cheaper than Qwen3.8 Flash?

Qwen3.8 Flash is cheaper on output tokens: $0.47/1M against $50.00/1M. Input tokens are $10.00/1M for Claude Fable 5.1 and $0.15/1M for Qwen3.8 Flash. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, Claude Fable 5.1 or Qwen3.8 Flash?

Both publish a 1M-token context window.

Which is better for coding, Claude Fable 5.1 or Qwen3.8 Flash?

AA Terminal-Bench 2.1: Claude Fable 5.1 91.4%, Qwen3.8 Flash 86.1% — Claude Fable 5.1 leads.

Are Claude Fable 5.1 and Qwen3.8 Flash open-weight models?

Claude Fable 5.1: API only. Qwen3.8 Flash: Restricted license. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Claude Fable 5.1 and Qwen3.8 Flash?

ModelCap currently lists 4 API providers for Claude Fable 5.1 and 1 for Qwen3.8 Flash, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Claude Fable 5.1 vs Qwen3.8 Flash comparison?

Every figure comes from the sealed ModelCap dataset published 3 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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