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BenchLM
Data

Inkling vs Step 5 Preview

Updated November 5, 2026. Rank says Step 5 Preview is ahead. Price, access, and your workload can each overturn that. Public scores include evidence status and uncertainty.

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Decision reading

Step 5 Preview has the higher public point estimate, 56.81 versus 48.1. Their conditional score ranges overlap. These ranges do not establish rank confidence. 7 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A
Thinking Machines Lab logo
Inkling

Thinking Machines Lab

48.1/100

Supported · Public rank #107

90% interval 30.6–65.6

Model B
StepFun logo
Step 5 Preview

StepFun

56.81/100

Estimated · Public rank #60

Conditional range 47.1–66.5

Shared results
7
Inkling only
17
Step 5 Preview only
17
Like-for-like categories
1 / 8
Supported: Inkling · Estimated: Step 5 Preview. Conditional ranges do not establish rank confidence.How the comparison works

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.

  • Chat turn cost

    1K fresh input + 500 output tokens

    Step 5 Preview

    Step 5 Preview 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

    Step 5 Preview

    Step 5 Preview has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
Show secondary and unsupported calls

  • Repository review cost

    50K fresh input + 3K output tokens

    Step 5 Preview

    Step 5 Preview 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

    Step 5 Preview is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like.

    Confidence: limited

  • Agentic work

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

    Not enough matched evidence

    Step 5 Preview is scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.

    Confidence: limited

  • Long documents

    Prompts that approach the documented context limit

    No clear pick

    The documented context windows are equal.

    Confidence: documented

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

33.0Inkling48.8Step 5 Preview

Directional only · BenchAlign v5.8

Step 5 Preview has the higher coding point estimate. Conditional score ranges do not establish rank confidence.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

Open the coding leaderboardShortlist models for this job
Same basis rules as the category table below

What is actually comparable

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

3 categories rest on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

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.

Too few matched category axes support a radar. The ruled list below shows only shared benchmark results; positions use each benchmark’s normalized display scale when available.

Bars run 0–100 on each benchmark’s normalized display scale

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign v5.8 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Knowledge

Like-for-like
Inkling
51.2
Supported · #76/177
Step 5 Preview
61.0
Supported · #44/177
Basis
BenchAlign v5.8 lane · 6 vs 2 public rows
Reading
Step 5 Preview leads · intervals overlap

Agentic

Directional only
Inkling
37.1
Supported · #82/135
Step 5 Preview
55.3
Estimated · #42/135
Basis
BenchAlign v5.8 lane · 5 vs 13 public rows
Reading
Directional only

Coding

Directional only
Inkling
33.0
Supported · #95/156
Step 5 Preview
48.8
Estimated · #47/156
Basis
BenchAlign v5.8 lane · 6 vs 6 public rows
Reading
Directional only

Multimodal

Directional only
Inkling
68.1
#38/58
Step 5 Preview
73.3
#32/58
Basis
Provisional lane · 2 vs 2 weighted rows
Reading
Directional only

Reasoning

Not comparable
Inkling
78.1
#10/26
Step 5 Preview
82.5
Unranked · 2 rankable rows
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Multilingual

Not comparable
Inkling
Not ranked
Step 5 Preview
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Instruction following

Not comparable
Inkling
87.6
#40/157
Step 5 Preview
Not ranked
Basis
Provisional lane · 1 vs 0 weighted rows
Reading
Not comparable

Math

Not comparable
Inkling
58.3
#11/12
Step 5 Preview
Not ranked
Basis
Provisional lane · 3 vs 0 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.8) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Supported evidence per lane · bars run 0–100Methodology

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

Inkling
$0.00421
Fits in one request
Step 5 Preview
$0.00235
Fits in one request

Step 5 Preview has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

Inkling
$0.10754
Fits in one request
Step 5 Preview
$0.0581
Fits in one request

Step 5 Preview has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

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

Inkling
$0.159
Fits in one request
Step 5 Preview
$0.057
Fits in one request

Step 5 Preview has the lower modeled cost

Costs use the listed standard API rates.

Cached input falls back to the list input rate only where a cached rate is unpublished

Specification differences

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

Cached-input rate

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

Inkling

$0.374 per 1M cached input tokens

Step 5 Preview

$0.05 per 1M cached input tokens

StepFun pricing and rate limits

Reasoning profile

Inkling

Hybrid

Step 5 Preview

Reasoning

Weight access

Inkling

Open Weight

Step 5 Preview

Open Weight

License

Inkling

Open Weight

Step 5 Preview

Open Weight

Release date

Inkling

2026-07-15

Step 5 Preview

2026-09-20

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
Step 5 Preview has the higher public point estimate, 56.81 versus 48.1. Their conditional score ranges overlap. These ranges do not establish rank confidence.
Workload cost
Repository review: $0.10754 vs $0.0581. Cache-heavy agent loop: $0.159 vs $0.057.
Context tradeoff
Both models list 1M.
Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, Inkling or Step 5 Preview?

Step 5 Preview has the higher public point estimate, 56.81 versus 48.1. Their conditional score ranges overlap. These ranges do not establish rank confidence. The page therefore keeps the decision tied to the specific documented workload.

Which is better for coding, Inkling or Step 5 Preview?

Step 5 Preview scores higher for coding on the public lane, 48.8 to 33. Step 5 Preview is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like. BenchLM does not name a winner for coding from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which is better for agentic tasks, Inkling or Step 5 Preview?

Step 5 Preview scores higher for agentic tasks on the public lane, 55.3 to 37.1. Step 5 Preview is scored on Estimated evidence for agentic tasks, so the reading is directional rather than like-for-like. BenchLM does not name a winner for agentic tasks from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which costs less, Inkling or Step 5 Preview?

For the stated presets, chat costs $0.00421 on Inkling and $0.00235 on Step 5 Preview; repository review costs $0.10754 and $0.0581; the cache-heavy agent loop costs $0.159 and $0.057. Costs use the listed standard API rates.

Which has the larger context window, Inkling or Step 5 Preview?

Both models list the same context window, 1M.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

Inkling
API / mo$4,913
Self-host / mo$27,962
Break-even344M/day
Step 5 Preview
API / mo$2,775
Self-host / mo$27,962
Break-even617M/day
Model the full break-even

Benchmark evidence

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

Browse raw public benchmark evidence41 rows

Agentic

  • Terminal-Bench 2.1

    Inkling63.8%
    Source
    Step 5 Preview85.0%
    Source

    Step 5 Preview leads this result

  • BrowseComp

    Inkling77.1%
    Source
    Step 5 Preview88.7%
    Source

    Step 5 Preview leads this result

  • MCP Atlas

    Inkling74.1%
    Source
    Step 5 Preview85.6%
    Source

    Step 5 Preview leads this result

  • Terminal-Bench 2.1 (Vals)

    Inkling47.6%
    Source
    Step 5 Preview—

    Not directly comparable

  • CWE-bench v1

    Inkling37.0%
    Source
    Step 5 Preview—

    Not directly comparable

  • Terminal-Bench 4.0

    Inkling—
    Step 5 Preview33.30%
    Source

    Not directly comparable

  • CyberGym

    Inkling—
    Step 5 Preview84.7%
    Source

    Not directly comparable

  • AutomationBench

    Inkling—
    Step 5 Preview44.0%
    Source

    Not directly comparable

  • Toolathlon-Verified

    Inkling—
    Step 5 Preview74.1%
    Source

    Not directly comparable

  • JobBench

    Inkling—
    Step 5 Preview59.0%
    Source

    Not directly comparable

  • APEX-Agents

    Inkling—
    Step 5 Preview37.8%
    Source

    Not directly comparable

  • DRACO

    Inkling—
    Step 5 Preview83.3%
    Source

    Not directly comparable

  • Agents' Last Exam

    Inkling—
    Step 5 Preview29.5%
    Source

    Not directly comparable

  • Hermes Index

    Inkling—
    Step 5 Preview32.8%
    Source

    Not directly comparable

  • Hermes Bench

    Inkling—
    Step 5 Preview69.2%
    Source

    Not directly comparable

Coding

  • SWE-bench Verified

    Inkling77.6%
    Source
    Step 5 Preview—

    Not directly comparable

  • SWE-bench Pro

    Inkling54.3%
    Source
    Step 5 Preview—

    Not directly comparable

  • Terminal-Bench 2.1

    Inkling63.8%
    Source
    Step 5 Preview85.0%
    Source

    Step 5 Preview leads this result

  • FrontierSWE v2

    Inkling4.1%
    Source
    Step 5 Preview—

    Not directly comparable

  • LiveCodeBench (Vals)

    Inkling85.5%
    Source
    Step 5 Preview—

    Not directly comparable

  • SWE-bench (Vals)

    Inkling77.6%
    Source
    Step 5 Preview—

    Not directly comparable

  • DeepSWE

    Inkling—
    Step 5 Preview67.7%
    Source

    Not directly comparable

  • SciCode

    Inkling—
    Step 5 Preview58.9%
    Source

    Not directly comparable

  • ProgramBench

    Inkling—
    Step 5 Preview80.5%
    Source

    Not directly comparable

  • sweMarathon

    Inkling—
    Step 5 Preview72.7%
    Source

    Not directly comparable

  • MLS-Bench Lite

    Inkling—
    Step 5 Preview40.5%
    Source

    Not directly comparable

Reasoning

  • CritPt

    Inkling—
    Step 5 Preview20.9%
    Source

    Not directly comparable

Multimodal

  • MMMU-Pro

    Inkling73.5%
    Source
    Step 5 Preview76%
    Source

    Step 5 Preview leads this result

  • CharXiv

    Inkling82%
    Source
    Step 5 Preview—

    Not directly comparable

  • CharXiv w/o tools

    Inkling78.1%
    Source
    Step 5 Preview—

    Not directly comparable

  • OfficeQA Pro

    Inkling—
    Step 5 Preview60.3%
    Source

    Not directly comparable

Knowledge

  • GPQA

    Inkling87.9%
    Source
    Step 5 Preview—

    Not directly comparable

  • GPQA-D

    Inkling87.9%
    Source
    Step 5 Preview93.5%
    Source

    Step 5 Preview leads this result

  • HLE

    Inkling46%
    Source
    Step 5 Preview46.5%
    Source

    Step 5 Preview leads this result

  • HLE w/o tools

    Inkling30%
    Source
    Step 5 Preview—

    Not directly comparable

  • GPQA Diamond (Vals)

    Inkling87.1%
    Source
    Step 5 Preview—

    Not directly comparable

  • MMLU-Pro (Vals)

    Inkling86.3%
    Source
    Step 5 Preview—

    Not directly comparable

Instruction following

  • IFBench

    Inkling79.8%
    Source
    Step 5 Preview—

    Not directly comparable

Math

  • AIME26

    Inkling97.1%
    Source
    Step 5 Preview—

    Not directly comparable

  • FrontierMath v2 (Tiers 1-3)

    Inkling33.333%
    Source
    Step 5 Preview—

    Not directly comparable

  • FrontierMath v2 (Tier 4)

    Inkling4.878%
    Source
    Step 5 Preview—

    Not directly comparable

41 public results · 7 shared

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Last updated November 5, 2026