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Model A
Grok 4.1 Fast

xAI

50.88/100

Supported · Public rank #130

90% interval 28.4–73.3

Grok 4.1 Fast vs Inkling

Updated August 29, 2026. Public scores include evidence status and uncertainty. They are not guarantees for a specific workload.

Thinking Machines Lab logo
Model B
Inkling

Thinking Machines Lab

67.02/100

Supported · Public rank #31

90% interval 60.0–74.0

Decision reading

The public evidence has no benchmark result shared by both models, so it does not support a quality verdict. Use the documented cost, context, and runtime rows instead.

0 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.

  • Long documents

    Prompts that approach the documented context limit

    Grok 4.1 Fast

    Grok 4.1 Fast has the larger documented context window.

    Confidence: documented

  • Chat turn cost

    1K fresh input + 500 output tokens

    Grok 4.1 Fast

    Grok 4.1 Fast has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Cache-heavy agent loop cost

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

    Grok 4.1 Fast

    Grok 4.1 Fast has the lower estimated token cost for this stated workload. Grok 4.1 Fast has no published cached-input rate, so cached tokens use its listed input rate.

    Confidence: rate-fallback

Show secondary and unsupported calls
  • Repository review cost

    50K fresh input + 3K output tokens

    Grok 4.1 Fast

    Grok 4.1 Fast has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • 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

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
0
Grok 4.1 Fast only
1
Inkling only
15
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
Grok 4.1 Fast
Not measured
Inkling
69.4
Weighted basis
0 vs 2 rows
Reading
Not comparable

Coding

Not comparable
Grok 4.1 Fast
Not measured
Inkling
68.6
Weighted basis
0 vs 2 rows
Reading
Not comparable

Reasoning

Not comparable
Grok 4.1 Fast
Not measured
Inkling
Not measured
Weighted basis
0 vs 0 rows
Reading
Not comparable

Knowledge

Not comparable
Grok 4.1 Fast
Not measured
Inkling
51.6
Weighted basis
0 vs 2 rows
Reading
Not comparable

Math

Not comparable
Grok 4.1 Fast
Not measured
Inkling
97.1
Weighted basis
0 vs 1 rows
Reading
Not comparable

Multilingual

Not comparable
Grok 4.1 Fast
Not measured
Inkling
Not measured
Weighted basis
0 vs 0 rows
Reading
Not comparable

Multimodal

Not comparable
Grok 4.1 Fast
Not measured
Inkling
76.5
Weighted basis
0 vs 2 rows
Reading
Not comparable

Instruction following

Not comparable
Grok 4.1 Fast
Not measured
Inkling
79.8
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

Grok 4.1 Fast
$0.00045
Fits in one request
Inkling
$0.00421
Fits in one request

Grok 4.1 Fast has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

Grok 4.1 Fast
$0.0115
Fits in one request
Inkling
$0.10754
Fits in one request

Grok 4.1 Fast has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

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

Grok 4.1 Fast
$0.049
Fits in one request
Cached input priced at the published list-input rate
Inkling
$0.159
Fits in one request

Grok 4.1 Fast has the lower modeled cost

Grok 4.1 Fast has no published cached-input rate, so cached tokens use its listed input rate.

Specification differences

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

Context window

Maximum documented context; output-token limits may be lower.

Grok 4.1 Fast

2M

Inkling

1M

API model ID

Grok 4.1 Fast

Not sourced

Inkling

Not sourced

Cached-input rate

A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.

Grok 4.1 Fast

Not published

Inkling

$0.374 per 1M cached input tokens

Documented inputs

Grok 4.1 Fast

Not sourced

Inkling

Not sourced

Documented outputs

Grok 4.1 Fast

Not sourced

Inkling

Not sourced

Provider availability

Grok 4.1 Fast

Not sourced

Inkling

Not sourced

Reasoning profile

Grok 4.1 Fast

Non-Reasoning

Inkling

Hybrid

Weight access

Grok 4.1 Fast

Proprietary

Inkling

Open Weight

License

Grok 4.1 Fast

Proprietary

Inkling

Open Weight

Release date

Grok 4.1 Fast

2025-11-19

Inkling

2026-07-15

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
The public evidence has no benchmark result shared by both models, so it does not support a quality verdict.
Workload cost
Repository review: $0.0115 vs $0.10754. Cache-heavy agent loop: $0.049 vs $0.159.
Context tradeoff
Grok 4.1 Fast has the larger documented window (2M).

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 evidence16 rows

Agentic

  • Gert Labs

    Grok 4.1 Fast47.32%
    Source
    Inkling

    Not directly comparable

  • Terminal-Bench 2.0

    Grok 4.1 Fast
    Inkling63.8%
    Source

    Not directly comparable

  • BrowseComp

    Grok 4.1 Fast
    Inkling77.1%
    Source

    Not directly comparable

  • MCP Atlas

    Grok 4.1 Fast
    Inkling74.1%
    Source

    Not directly comparable

Coding

  • SWE-bench Verified

    Grok 4.1 Fast
    Inkling77.6%
    Source

    Not directly comparable

  • SWE-bench Pro

    Grok 4.1 Fast
    Inkling54.3%
    Source

    Not directly comparable

  • Terminal-Bench 2.0

    Grok 4.1 Fast
    Inkling63.8%
    Source

    Not directly comparable

Knowledge

  • GPQA

    Grok 4.1 Fast
    Inkling87.9%
    Source

    Not directly comparable

  • GPQA-D

    Grok 4.1 Fast
    Inkling87.9%
    Source

    Not directly comparable

  • HLE

    Grok 4.1 Fast
    Inkling46%
    Source

    Not directly comparable

  • HLE w/o tools

    Grok 4.1 Fast
    Inkling30%
    Source

    Not directly comparable

Math

  • AIME26

    Grok 4.1 Fast
    Inkling97.1%
    Source

    Not directly comparable

Multimodal

  • MMMU-Pro

    Grok 4.1 Fast
    Inkling73.5%
    Source

    Not directly comparable

  • CharXiv

    Grok 4.1 Fast
    Inkling82%
    Source

    Not directly comparable

  • CharXiv w/o tools

    Grok 4.1 Fast
    Inkling78.1%
    Source

    Not directly comparable

Instruction following

  • IFBench

    Grok 4.1 Fast
    Inkling79.8%
    Source

    Not directly comparable

Frequently asked questions

Which is better, Grok 4.1 Fast or Inkling?

The public evidence has no benchmark result shared by both models, so it does not support a quality verdict. The page therefore keeps the decision tied to the specific documented workload.

Which is better for coding, Grok 4.1 Fast or Inkling?

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, Grok 4.1 Fast or Inkling?

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, Grok 4.1 Fast or Inkling?

For the stated presets, chat costs $0.00045 on Grok 4.1 Fast and $0.00421 on Inkling; repository review costs $0.0115 and $0.10754; the cache-heavy agent loop costs $0.049 and $0.159. Grok 4.1 Fast has no published cached-input rate, so cached tokens use its listed input rate.

Which has the larger context window, Grok 4.1 Fast or Inkling?

Grok 4.1 Fast has the larger documented context window: 2M, compared with 1M.

Related comparisons

Last updated August 29, 2026

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