Skip to main content
Radar

Five or fewer confirmed AI changes, with original sources, on mornings when something changed.A free source-linked morning brief.

See the free Radar Brief
BenchLM
Anthropic logo
Model A
Claude Fable 5.1

Anthropic

82.74/100

Estimated · Public rank #1

90% interval 71.2–94.3

Claude Fable 5.1 vs Nemotron 3.5 Lightning 30B A3B NVFP4

Updated September 1, 2026. Public scores include evidence status and uncertainty. They are not guarantees for a specific workload.

NVIDIA logo
Model B
Nemotron 3.5 Lightning 30B A3B NVFP4

NVIDIA

26.55/100

Estimated · Public rank #219

90% interval 16.7–36.4

Decision reading

Claude Fable 5.1 has the higher public score, 82.74 versus 26.55, and the 90% score intervals do not overlap.

2 results are shared. Category rows based on different benchmark sets are marked directional and do not name a winner.

Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

No workload recommendation clears the current evidence threshold.

Use the matched evidence, workload costs, and sourced specifications below instead of treating a point score as a universal answer.

Show secondary and unsupported calls

  • Coding work

    Code generation, repair, and software-engineering tasks

    Not enough matched evidence

    No shared weighted benchmark basis supports a winner.

    Confidence: limited

  • Agentic work

    Tool use, computer use, and multi-step task completion

    Not enough matched evidence

    No shared weighted benchmark basis supports a winner.

    Confidence: limited

  • Long documents

    Prompts that approach the documented context limit

    No clear pick

    The documented context windows are equal.

    Confidence: documented

  • Chat turn cost

    1K fresh input + 500 output tokens

    Not enough matched evidence

    A complete comparable API-rate estimate is not available for both models.

    Confidence: listed-rates

  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    Not enough matched evidence

    A complete comparable API-rate estimate is not available for both models.

    Confidence: listed-rates

  • Repository review cost

    50K fresh input + 3K output tokens

    Not enough matched evidence

    A complete comparable API-rate estimate is not available for both models.

    Confidence: listed-rates

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

Shared results
2
Claude Fable 5.1 only
16
Nemotron 3.5 Lightning 30B A3B NVFP4 only
11
Like-for-like categories
0 / 8

Category results, on a stated basis

Each row states whether both averages use the same weighted benchmark set. Directional and not-comparable rows remain visible, but they never receive a winner in this template.

Agentic

Not comparable
Claude Fable 5.1
Not measured
Nemotron 3.5 Lightning 30B A3B NVFP4
29.1
Weighted basis
0 vs 2 rows
Reading
Not comparable

Coding

Not comparable
Claude Fable 5.1
81.2
Nemotron 3.5 Lightning 30B A3B NVFP4
42.1
Weighted basis
1 vs 2 rows
Reading
Not comparable

Reasoning

Not comparable
Claude Fable 5.1
90.0
Nemotron 3.5 Lightning 30B A3B NVFP4
Not measured
Weighted basis
1 vs 0 rows
Reading
Not comparable

Knowledge

Not comparable
Claude Fable 5.1
65.0
Nemotron 3.5 Lightning 30B A3B NVFP4
80.5
Weighted basis
1 vs 2 rows
Reading
Not comparable

Math

Not comparable
Claude Fable 5.1
Not measured
Nemotron 3.5 Lightning 30B A3B NVFP4
Not measured
Weighted basis
0 vs 0 rows
Reading
Not comparable

Multilingual

Not comparable
Claude Fable 5.1
Not measured
Nemotron 3.5 Lightning 30B A3B NVFP4
Not measured
Weighted basis
0 vs 0 rows
Reading
Not comparable

Multimodal

Not comparable
Claude Fable 5.1
Not measured
Nemotron 3.5 Lightning 30B A3B NVFP4
Not measured
Weighted basis
0 vs 0 rows
Reading
Not comparable

Instruction following

Not comparable
Claude Fable 5.1
Not measured
Nemotron 3.5 Lightning 30B A3B NVFP4
72.9
Weighted basis
0 vs 1 rows
Reading
Not comparable

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

A shared-evidence shape is not available.

BenchLM does not draw a radar or infer missing axes when the matched evidence is too sparse.

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

Claude Fable 5.1
$0.035
Fits in one request
Nemotron 3.5 Lightning 30B A3B NVFP4
Self-hosted; infrastructure cost varies
Fits in one request

Nemotron 3.5 Lightning 30B A3B NVFP4 has no comparable published API token rate.

Repository review

50K fresh input + 3K output tokens

Claude Fable 5.1
$0.65
Fits in one request
Nemotron 3.5 Lightning 30B A3B NVFP4
Self-hosted; infrastructure cost varies
Fits in one request

Nemotron 3.5 Lightning 30B A3B NVFP4 has no comparable published API token rate.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

Claude Fable 5.1
$0.75
Fits in one request
Nemotron 3.5 Lightning 30B A3B NVFP4
Self-hosted; infrastructure cost varies
Fits in one request
Cached-input rate unavailable

Nemotron 3.5 Lightning 30B A3B NVFP4 has no comparable published API token rate.

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Documented inputs

Claude Fable 5.1

Not sourced

Nemotron 3.5 Lightning 30B A3B NVFP4

Not sourced

Documented outputs

Claude Fable 5.1

Not sourced

Nemotron 3.5 Lightning 30B A3B NVFP4

Not sourced

Provider availability

Claude Fable 5.1

Generally Available · Claude API, Claude products, AWS, Google Cloud, Microsoft Azure

Anthropic Fable 5.1 and Mythos 5.1 launch

Nemotron 3.5 Lightning 30B A3B NVFP4

Not sourced

Reasoning profile

Claude Fable 5.1

Reasoning

Nemotron 3.5 Lightning 30B A3B NVFP4

Reasoning

Weight access

Claude Fable 5.1

Proprietary

Nemotron 3.5 Lightning 30B A3B NVFP4

Open Weight

License

Claude Fable 5.1

Proprietary

Nemotron 3.5 Lightning 30B A3B NVFP4

Open Weight

Release date

Claude Fable 5.1

2026-09-01

Nemotron 3.5 Lightning 30B A3B NVFP4

2026-08-11

If you already use one of these models
Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
Claude Fable 5.1 has the higher public score, 82.74 versus 26.55, and the 90% score intervals do not overlap.
Workload cost
A complete comparable API-rate estimate is not available for both models.
Context tradeoff
Both models list 1M.

Run the same representative tasks against both endpoints before changing production traffic.

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence29 rows

Agentic

  • Terminal-Bench 4.0

    Claude Fable 5.155.80%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • Terminal-Bench-Science 0.1

    Claude Fable 5.152.6%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • OSWorld 2.0

    Claude Fable 5.141.7%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • AutomationBench

    Claude Fable 5.131.4%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • Toolathlon-Verified

    Claude Fable 5.177.8%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • Toolathlon Verified Pass@3

    Claude Fable 5.181.5%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • Toolathlon Verified Pass³

    Claude Fable 5.173.1%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • Toolathlon Verified avg. turns

    Claude Fable 5.123.7 turns
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • Terminal-Bench 2.0

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP423.5%
    Source

    Not directly comparable

  • PinchBench

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP483.4%
    Source

    Not directly comparable

  • BrowseComp

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP436.8%
    Source

    Not directly comparable

  • τ³-bench results

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP49.5%
    Source

    Not directly comparable

Coding

  • SWE-bench Pro

    Claude Fable 5.181.2%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • SWE Multilingual

    Claude Fable 5.189.1%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP436.5%
    Source

    Claude Fable 5.1 leads this result

  • SWE Multimodal

    Claude Fable 5.154.7%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • deepSwe

    Claude Fable 5.167.4%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • ProgramBench

    Claude Fable 5.187.6%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • cursorBench32

    Claude Fable 5.173.4%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • SWE-bench Verified

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP452.8%
    Source

    Not directly comparable

  • Terminal-Bench 2.0

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP423.5%
    Source

    Not directly comparable

  • SciCode

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP431.4%
    Source

    Not directly comparable

Reasoning

  • ARC-AGI-1

    Claude Fable 5.197.50%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • ARC-AGI-2

    Claude Fable 5.190%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

Knowledge

  • HLE

    Claude Fable 5.165%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP4—

    Not directly comparable

  • HLE w/o tools

    Claude Fable 5.160.9%
    Source
    Nemotron 3.5 Lightning 30B A3B NVFP410.5%
    Source

    Claude Fable 5.1 leads this result

  • GPQA

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP475.6%
    Source

    Not directly comparable

  • GPQA-D

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP475.6%
    Source

    Not directly comparable

  • MMLU-Pro

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP481.6%
    Source

    Not directly comparable

Instruction following

  • IFBench

    Claude Fable 5.1—
    Nemotron 3.5 Lightning 30B A3B NVFP472.9%
    Source

    Not directly comparable

Frequently asked questions

Which is better, Claude Fable 5.1 or Nemotron 3.5 Lightning 30B A3B NVFP4?

Claude Fable 5.1 has the higher public score, 82.74 versus 26.55, and the 90% score intervals do not overlap. That is the clearest overall quality signal in the current public data.

Which is better for coding, Claude Fable 5.1 or Nemotron 3.5 Lightning 30B A3B NVFP4?

The published evidence does not provide a shared weighted coding basis for both models, so BenchLM does not name a coding winner.

Which is better for agentic tasks, Claude Fable 5.1 or Nemotron 3.5 Lightning 30B A3B NVFP4?

The published evidence does not provide a shared weighted agentic tasks basis for both models, so BenchLM does not name a agentic tasks winner.

Which costs less, Claude Fable 5.1 or Nemotron 3.5 Lightning 30B A3B NVFP4?

Both models do not have comparable published API token rates, so this page does not name a universal price winner.

Which has the larger context window, Claude Fable 5.1 or Nemotron 3.5 Lightning 30B A3B NVFP4?

Both models list the same context window, 1M.

Related comparisons

Compare API pricing Read the methodology Open the model selector

Last updated September 1, 2026

Watch Claude Fable 5.1 vs Nemotron 3.5 Lightning 30B A3B NVFP4

One weekly email when material rank, price, or benchmark evidence changes make this matchup worth revisiting.

Read a sample issue

Join 2,000+ readers.