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Model comparison · accepted catalogue facts 2026-10-21

Claude Fable 5 vs DeepSeek V4.1 Flash

Neither model has both an equal-or-higher measured score and an equal-or-lower estimated price in this pair. Retaining your current model is a valid outcome.

Editorial comparison: Flagship capability vs high-speed tier: Claude Fable 5 (Anthropic) vs DeepSeek V4.1 Flash (DeepSeek) Inclusion does not recommend either model.

Claude Fable 5

LMArena general · Elo · higher is better

Scale starts at 1040 Elo

1491.0

Balanced effective USD / 1M tokens · lower is better

$20.00/M

DeepSeek V4.1 Flash

LMArena general · Elo · higher is better

Scale starts at 1040 Elo

1462.5

Balanced effective USD / 1M tokens · lower is better

$0.182/M

Price under confirmation since Oct 12, 2026

In-Depth Analysis

Claude Fable 5 vs DeepSeek V4.1 Flash: Measured Technical Breakdown

Comprehensive comparison across measured human-preference evaluation, effective production token costs, architectural limits, and migration trade-offs.

Measured Capability (LMArena)
Claude Fable 5 leads by 28.5 Elo

Claude Fable 5: 1491 ±4.3 · DeepSeek V4.1 Flash: 1462.5 ±6.29 Statistically significant preference separation

Cost Comparison Across Canonical Production Workloads

Rates represent effective cost per 1M tokens under standard token blends. Cached prompt reads are factored according to workload context reuse.

Workload & RatioClaude Fable 5DeepSeek V4.1 FlashCost DifferenceAdvantage
Balanced 3 tokens in per 1 out$20.00 /1M tokens$0.182 /1M tokens$19.82 (99% diff)DeepSeek V4.1 Flash costs less
Summarise Huge input, tiny output$9.44 /1M tokens$0.067 /1M tokens$9.37 (99% diff)DeepSeek V4.1 Flash costs less
Chat Long cached system prompt$23.30 /1M tokens$0.247 /1M tokens$23.05 (99% diff)DeepSeek V4.1 Flash costs less
Code gen Output dominates$33.28 /1M tokens$0.360 /1M tokens$32.92 (99% diff)DeepSeek V4.1 Flash costs less
Agentic Context replayed each turn$10.65 /1M tokens$0.105 /1M tokens$10.54 (99% diff)DeepSeek V4.1 Flash costs less

Architectural & Operational Specifications

SpecificationClaude Fable 5DeepSeek V4.1 FlashOperational Note
Context window1,000,000 tokens1,048,576 tokens—
Max output generation128,000 tokens943,718 tokensDeepSeek V4.1 Flash allows longer single-turn completions
Base input price$10.00 / 1M tokens$0.053 / 1M tokensDeepSeek V4.1 Flash input rate is cheaper
Base output price$50.00 / 1M tokens$0.570 / 1M tokensDeepSeek V4.1 Flash output rate is cheaper
Cached input price$1.00 / 1M tokens$0.010 / 1M tokensDeepSeek V4.1 Flash offers lower cached prompt cost
Reasoning & thinking tokensSupported; standard ratesSupported; standard rates—
Input modalitiestext, image, filetext, image—
Tool calling / function useSupportedSupported—
Open weights & licenceProprietary (proprietary)Proprietary (API-only)DeepSeek V4.1 Flash allows independent hosting or local deployment
Provider & reseller marketAnthropic · 6 provider offersDeepSeek · 31 provider offers (11.19× spread)—

When to Choose Claude Fable 5

  • Higher measured general capability (1491 Elo on human evaluation).
  • Broader multimodal input support: text, image, file.
  • Direct integration with Anthropic tooling and API features.
Risks when moving from DeepSeek V4.1 Flash → Claude Fable 5:
  • Context window: 1,048,576 → 1,000,000 tokens.
  • Output limit: 943,718 → 128,000 tokens.

When to Choose DeepSeek V4.1 Flash

  • Larger context window (1,048,576 tokens) for long-document or repo-level context.
  • Higher maximum completion limit (943,718 tokens).
  • Direct integration with DeepSeek tooling and API features.
Risks when moving from Claude Fable 5 → DeepSeek V4.1 Flash:
  • file input is not supported by the candidate.

Detailed Evidence Passports & Independent Audits

Claude Fable 5 Full model card, pricing ladder & provider offers → DeepSeek V4.1 Flash Full model card, pricing ladder & provider offers → Alternatives to Claude Fable 5 Better-and-cheaper dominance audit → Alternatives to DeepSeek V4.1 Flash Better-and-cheaper dominance audit →

Compare · model decision

Choose two or three models

Inspect the differences, estimate your workload and keep the evidence. All standard catalogue models are available, including unrated ones.

Catalogue facts
2026-10-21

2 / 3 selected · 0 requirements
Open public comparison link
Public workload and requirements

These settings are included in the share link. The fixed-request scenario and private evaluation data below are excluded.

A ↔ B

Neither model has both an equal-or-higher measured score and an equal-or-lower estimated price in this pair. Retaining your current model is a valid outcome.

Estimated blend: 75% input, 25% output; 0% cached input. Base context tier. Prompt length selects the billing tier. An unlisted cache-read rate uses that tier’s full input rate in this blend; missing required input or output rates prevent an estimate. The fixed-request estimate below validates actual context and output limits and requires a published cache-read rate when cache hits are assumed.

What changes between these models

Quality first, then estimated price. LMArena scores are human-preference measurements, not a benchmark of your application. A missing score is unrated.

  • Claude Fable 5 · Meets the stated model requirements
  • DeepSeek V4.1 Flash · Meets the stated model requirements
Material differences and unknown evidence. Deltas compare each model with model A. Unknown facts remain visible.
Measured factA Claude Fable 5B DeepSeek V4.1 Flash
LMArena general score (Elo)1,4911,462.5Δ vs A: -28.5 Elo
Score interval half-width (± Elo)4.36.29Δ vs A: +1.99 Elo
Benchmark reasoning efforthighmax
LMArena document score (Elo)1,496.1Unknown
Estimated effective USD / 1M tokens$20$0.18225Δ vs A: -19.81775 USD/M
Base input USD / 1M tokens$10$0.053Δ vs A: -9.947 USD/M
Base output USD / 1M tokens$50$0.57Δ vs A: -49.43 USD/M
Base cached-input USD / 1M tokens$1$0.01Δ vs A: -0.99 USD/M
Price statusAs of the catalogue dateUnder confirmation since 2026-10-12
Context window (tokens)1,000,0001,048,576Δ vs A: +48,576 tokens
Output limit (tokens)128,000943,718Δ vs A: +815,718 tokens
Input modalitiestext, image, filetext, image
Open weightsNot supportedUnknown
Recorded licenceproprietaryUnknown
Model providerAnthropicDeepSeek
Distinct sellers in the catalogue529Δ vs A: +24
Serving precision differs across offersNot supportedSupportedΔ vs A: +1
Recorded retirement dateUnknownUnknown
3 shared measured facts
Shared measured facts. Deltas compare each model with model A. Unknown facts remain visible.
Measured factA Claude Fable 5B DeepSeek V4.1 Flash
Tool useSupportedSupportedΔ vs A: 0
ReasoningSupportedSupportedΔ vs A: 0
Retirement evidenceNone announced; not a guaranteeNone announced; not a guarantee

Provider counts and precision flags describe catalogue offers. They do not establish the precision, availability, region, tool behaviour or limits of your chosen endpoint. Open each model’s provider table before switching.

Complete price ladders and billing conditions

Claude Fable 5

Rates below are USD per 1M tokens. A threshold selects that whole input/output rate pair.

Input-token thresholdInputOutputCached input
Base, up to and including first threshold$10$50$1

DeepSeek V4.1 Flash

Rates below are USD per 1M tokens. A threshold selects that whole input/output rate pair.

Input-token thresholdInputOutputCached input
Base, up to and including first threshold$0.053$0.57$0.01
Migration preflight · compare each candidate with model A

Keeping Claude Fable 5 is a valid decision. No pairwise comparison certifies a drop-in replacement.

Claude Fable 5 → DeepSeek V4.1 Flash

Known loss or failed requirement

  • file input is not supported by the candidate.
  • Provider endpoint, serving precision, availability and task success need your own verification. Catalogue model capabilities do not certify an endpoint.
Check alternatives to Claude Fable 5

Estimate a fixed request shape

Private to this tab unless you save locally or explicitly export private details. These are estimates, not observed invoices. Cross-model token counts and task success are assumptions.

0.1 extra attempts means 10 extra full attempts per 100 requests. Cache writes, tool charges, taxes and unlisted charges are excluded.

  • Claude Fable 5Estimated total: $45 1,000 full attempts · base rates
  • DeepSeek V4.1 FlashEstimated total: $0.391 1,000 full attempts · base rates
Prompt and output sensitivity · sampled scenarios

Every point recalculates the entire request shape. Tier-boundary samples include one token below, at and above each threshold. Ordering between samples is not guaranteed. Lowest known cost excludes unknown estimates and is not a replacement recommendation.

Vary input; hold output, requests, cache and retries fixed.
Input tokensClaude Fable 5DeepSeek V4.1 FlashCoverage
2,000$45$0.391Lowest knownAll computed
4,096$65.96$0.502088Lowest knownAll computed
32,768$352.68$2.021704Lowest knownAll computed
131,072$1,335.72$7.231816Lowest knownAll computed
Vary output; hold input, requests, cache and retries fixed.
Output tokensClaude Fable 5DeepSeek V4.1 Flash
128$26.4$0.17896
2,048$122.4$1.27336
8,192$429.6$4.77544

Bring your observed evaluation results

JSON is parsed locally. Prompts, filenames, individual responses and extra fields are not retained. Import only aggregate measurements for selected models. Task/version labels do not establish that two evaluations used the same dataset.

Expected format
[{"model":"provider/exact-model-id","task":"support-answer","version":"rubric-1","attempts":100,"successes":84,"costUsd":2.4,"latencyMs":950}]

Use the exact catalogue ID. Replace the example values with observed measurements. Omit costUsd or latencyMs when they are unknown. No public score is inferred from these observations.

Keep the decision and its evidence

A portable record retains selected facts, complete tier ladders, public requirements and the publication manifest. It also embeds the full permitted public catalogue to verify the input artifact checksum. Files are larger for this reason (up to 2 MB); local storage is limited to 12 records. Team review is local to this browser; there is no hosted collaboration.

Saving is opt-in and includes private review fields. Shared comparison links never include them. Version 1 Check references remain separate and are not overwritten or guessed into this format.

Saved local decisions · 0

No version 2 decision records are stored in this browser.

Questions this page answers

Is Claude Fable 5 a better-and-cheaper replacement for DeepSeek V4.1 Flash?

Neither model has both an equal-or-higher measured score and an equal-or-lower estimated price in this pair. Retaining your current model is a valid outcome.

Which model is higher rated: Claude Fable 5 or DeepSeek V4.1 Flash?

Claude Fable 5 scores higher on LMArena general (1491.0 ±4.3) compared to DeepSeek V4.1 Flash (1462.5 ±6.3), a margin of 28.5 Elo points. The measured confidence intervals do not overlap, demonstrating a statistically significant preference lead on human evaluations.

Which model is more cost-effective: Claude Fable 5 or DeepSeek V4.1 Flash?

On a standard balanced workload (3 prompt tokens per 1 generated token), DeepSeek V4.1 Flash costs $0.182 (price under confirmation since 2026-10-12) per 1M tokens versus $20.00 for Claude Fable 5. Claude Fable 5 is approximately 109.7× the price of DeepSeek V4.1 Flash. Base input rates are $10.00 for Claude Fable 5 and $0.053 for DeepSeek V4.1 Flash; base output rates are $50.00 for Claude Fable 5 and $0.570 for DeepSeek V4.1 Flash.

How do their context windows and generation limits compare?

Claude Fable 5 provides a 1,000,000-token context window with a maximum output limit of 128,000 tokens. DeepSeek V4.1 Flash provides a 1,048,576-token context window with a maximum output of 943,718 tokens.

What capabilities are lost when switching between Claude Fable 5 and DeepSeek V4.1 Flash?

Switching from Claude Fable 5 to DeepSeek V4.1 Flash involves: file input is not supported by the candidate. Conversely, moving from DeepSeek V4.1 Flash to Claude Fable 5 involves: Context window: 1,048,576 → 1,000,000 tokens; Output limit: 943,718 → 128,000 tokens. Run test suites on your specific prompt templates and tool declarations before cutting over production traffic.

Can Claude Fable 5 or DeepSeek V4.1 Flash be self-hosted or deployed privately?

Both Claude Fable 5 and DeepSeek V4.1 Flash are proprietary cloud models offered via managed API endpoints. Claude Fable 5 is served by Anthropic and 6 catalogue offers, while DeepSeek V4.1 Flash is served by DeepSeek and 31 catalogue offers.

What is included in this comparison?

Accepted model capabilities, context and output limits, complete price-tier ladders, independent LMArena measurements and missing evidence. Provider endpoint precision and application success still need verification.

Can I compare a different workload or keep a decision record?

Yes. Change the public workload, prompt length and requirements in the comparison workspace. Fixed-request scenarios, aggregate evaluations and review notes stay local unless explicitly exported.

Evidence & Ask
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