ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GPT-5 Pro vs Inkling

Inkling comes out ahead, 59 to 54 on our weighted score, and it is the cheaper option too.

  1. OpenAI

    GPT-5 Pro

    Released Oct 6, 2025

    54/100
    • ECI150.3
    • Price$15.00 / $120.00
    • Context400K
    Full specs Remove GPT-5 Pro
  2. Our pick

    Thinking Machines

    Inkling

    Released Jul 15, 2026

    59/100
    • ECI148.6
    • Price$3.74 / $9.36
    • Context1.05M
    Full specs Remove Inkling

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Inkling is our pick

Inkling is the better all-round choice, scoring 59/100 against GPT-5 Pro (54). It leads on price and context window. GPT-5 Pro wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5 ProCapabilities Index (ECI): GPT-5 Pro 150.3 · Inkling 148.6
  • Lowest priceInklingInkling $5.14 · GPT-5 Pro $41.25 per 1M tokens (3:1 blend)
  • Longest contextInklingInkling 1,048,576 · GPT-5 Pro 400,000 tokens
  • Widest inputsInklingGPT-5 Pro: Text, Images · Inkling: Text, Images, Audio
  • Self-hostingInklingPublishes downloadable weights (Apache-2.0)
How the score is built
MeasureWeightGPT-5 ProInkling
CapabilityCapabilities Index (ECI)50%7876
Price25%016
Inputs & features15%7070
Context window10%4461
Overall100%54/10059/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GPT-5 Pro vs Inkling specifications side by side
SpecificationGPT-5 ProOpenAIInklingThinking Machines
Capability
Capabilities Index (ECI)150.3 (best)148.6
ECI rank#46 of 148 (best)#57 of 148
GPQA DiamondGraduate-level science questions—88.3%
FrontierMath Tiers 1–3Research-level mathematics55.8% (best)33.3%
OTIS Mock AIME 2024–2025Competition mathematics—88.9%
SimpleQA VerifiedShort factual questions—40.3%
Price per million tokens
Input$15.00$3.74 (best)
Output$120.00$9.36 (best)
Cached input—$0.748
Blended (3:1)$41.25$5.14 (best)
Long-context rateSame rateSame rate
Price sourceOfficial OpenAI APIOfficial Thinking Machines API
Limits
Context window400,000 tokens1,048,576 tokens (best)
Max output272,000 tokens1,048,576 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoYes
VideoNoNo
ReasoningYeshighYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesNo
Availability
WeightsProprietaryOpenApache-2.0
API model IDgpt-5-prothinkingmachines/Inkling:peft:262144
API providers1223 (best)
ReleasedOct 6, 2025Jul 15, 2026
Knowledge cutoffSep 30, 2024—
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • GPT-5 Pro$390.00
  • Inkling$56.12
04 — Questions

Which should you choose?

Which is better: GPT-5 Pro or Inkling?

Inkling is the better all-round choice, scoring 59/100 against GPT-5 Pro (54). It leads on price and context window. GPT-5 Pro wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5 Pro or Inkling?

Inkling is cheaper at $3.74 input / $9.36 output per million tokens (official Thinking Machines API price). GPT-5 Pro costs $15.00 input / $120.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $5.14 per million tokens for Inkling versus $41.25 for GPT-5 Pro (8× as much).

Which scores higher on benchmarks?

GPT-5 Pro scores higher on the Capabilities Index (ECI): GPT-5 Pro 150.3 (#46 of 148) and Inkling 148.6 (#57 of 148). The confidence ranges of the top two overlap (148.5–152.8 vs 145.7–150.6), so treat the gap as small. On individual benchmarks: FrontierMath Tiers 1–3 — GPT-5 Pro 55.8%, Inkling 33.3%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5 Pro and Inkling yet, so there is no like-for-like coding score. On overall capability, GPT-5 Pro leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

Inkling has the largest context window at 1,048,576 tokens, against 400,000 for GPT-5 Pro. Maximum output per response: GPT-5 Pro up to 272,000, Inkling up to 1,048,576 tokens.

Which can read images, PDFs, audio or video?

GPT-5 Pro accepts text and images; Inkling accepts text, images and audio. Inkling handles the widest range of inputs.

Are any of these open source?

Inkling publishes its weights (Apache-2.0) and can be self-hosted; GPT-5 Pro is proprietary.

Which is newer?

Inkling is the newest, released Jul 15, 2026. GPT-5 Pro came out Oct 6, 2025. Knowledge cutoff: GPT-5 Pro Sep 30, 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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