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AI Choice Engine

Model comparison

Claude Fable 5.1 vs SWE-1.7

Anthropic against Cognition, compared on context, price, and attributed benchmark results.

Recorded profile verification October 2, 2026Individual provider fields may changeEvidence confidence: Insufficient data — see receipts below

Anthropic

Claude Fable 5.1

Frontier

vs

Cognition

SWE-1.7

Frontier

AI model capability comparison
SpecificationClaude Fable 5.1SWE-1.7
ProviderAnthropicCognition
TierFrontierFrontier
Context window1MNot verifiedUnverified
Max output128KNot verifiedUnverified
Input / 1M tokens$10Not verifiedUnverified
Output / 1M tokens$50Not verifiedUnverified
WeightsClosedNot verifiedUnverified
ParametersNot verifiedUnverifiedNot verifiedUnverified
Reasoning levelslow, medium, high, xhigh, maxNot verifiedUnverified
Modalitiestext, imagetext
API model idclaude-fable-5-1Not verifiedUnverified
ReleasedSeptember 1, 2026July 8, 2026
Artificial Analysis Intelligence Index [max] · source date Claude Fable 5.1: 2026-10-0153Not verifiedUnverified
Humanity's Last Exam · source date Claude Fable 5.1: 2026-09-0165Not verifiedUnverified
Terminal-Bench 2.1 · source date Claude Fable 5.1: 2026-09-2691.4Not verifiedUnverified
DeepSWE 1.1 · source date Claude Fable 5.1: 2026-09-0367.4Not verifiedUnverified

Dates beside benchmark scores refer to the linked source’s publication or capture date unless that source explicitly states when it measured the result. A shared URL alone does not establish comparable runs; unverified setups are marked. Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

Where each score comes from, and how far it can be compared across models.

Pricing tiers

Claude Fable 5.1: Standard $10/$50 per MTok with no long-context surcharge. Cache reads $0.25, versus Fable 5's $1; 5-minute writes $12.50 and 1-hour writes $20. Batch $5/$25. US-only inference adds 10% where supported. Adaptive thinking is always on, default effort high; knowledge cutoff Jun 2026. Retirement not sooner than September 1, 2027.

SWE-1.7: In-product model access and billing vary by plan/account. Exact current model-specific rates were not recovered; the authenticated List Models response is the account source of truth. Historical free/speed offers are not current generic API prices.

FrontierRecord checked October 1, 2026

Claude Fable 5.1

Claude Fable 5.1 is Anthropic's model for the most demanding reasoning and long-horizon agentic work at $10/$50 — Anthropic now recommends Opus 5.5 as the default for most workloads.

Best for

  • Frontier agents
  • Hardest reasoning work
  • Fable 5 workloads at the same price

Watch out

Standard token rates are 2.5x Opus 5.5's. Forced tool use errors; thinking blocks are model/conversation-bound, so editing earlier turns or switching models can invalidate them. Display updates and per-message effort are beta. Match benchmark settings and evaluate pinned workloads before migrating.

FrontierRecord checked October 2, 2026

SWE-1.7

Cognition's previous flagship software-engineering agent model, trained from Kimi K2.7 and offered within Devin.

Best for

  • Comparing an enabled predecessor agent with SWE-2 in Devin

Watch out

Exact context/output caps, stable generic inference API ID, downloadable weights/licence and model-specific numeric parameter count are unverified. The authenticated List Models endpoint returns account model-menu UIDs and plan-specific pricing; its placeholder examples are not live prices or general inference endpoints. Do not inherit base-model, harness or sibling benchmark scores; vendor speed/evaluation claims are not independent cross-model results. Kimi K2.7 ancestry does not establish matching checkpoint licence, hosted limits, weights or benchmark results.

When the cheaper one wins

One of these rows is missing a verified output price, so this page will not name a cheaper winner. Run the model picker against the actual job instead of guessing.

Run the model picker

Evidence confidence: Insufficient data

How strong and complete the evidence behind this comparison is — not a prediction of which model is better. Hard limitations apply: missing pricing; evidence too sparse.

  • Pricing incomplete — No verified token pricing for SWE-1.7.
  • 1/5 core specs verified on both sides — Not published for at least one side: context window, max output, parameter count, reasoning levels.
  • No directly aligned benchmark setup — No benchmark has matching cited sources, source dates, units, effort and recorded run details on both models.
  • Verified within the last 90 days — Older of the two catalog checks was 25 days ago.
  • Both models carry source citations — Each side has at least two catalog sources on record.

Source receipts

Each catalog figure was checked against the provider or an independent second source on the date shown.

Related comparisons

Diving deeper on one model? Claude Fable 5.1 · SWE-1.7

Common questions

Claude Fable 5.1 vs SWE-1.7

Answered from the verified figures on this page rather than general guidance.

Should I use Claude Fable 5.1 or SWE-1.7?
Both are classified in our frontier tier; this editorial grouping does not imply equal capability. Claude Fable 5.1 is a candidate for frontier agents; SWE-1.7 is a candidate for comparing an enabled predecessor agent with swe-2 in devin. Compare accuracy, tool reliability, latency and cost on representative tasks.

Next step

Choosing between them

The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.

These two models match on every verified catalog figure — the decision comes down to provider preference, availability, and workload fit rather than published numbers.

Run the model pickerEstimate stack costAll model comparisons

Choosing a harness rather than a model — Cursor, Copilot, Claude Code, Windsurf, or Lovable? Compare agentic harnesses · Latest releases.