ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GLM-4.5-Air vs GLM-4.5-Flash

GLM-4.5-Flash comes out ahead, 65 to 49 on our weighted score, and it is the cheaper option too.

  1. Z.ai (Zhipu)

    GLM-4.5-Air

    Released Jul 28, 2025

    49/100
    • ECI—
    • Price$0.20 / $1.10
    • Context131K
    Full specs Remove GLM-4.5-Air
  2. Our pick

    Z.ai (Zhipu)

    GLM-4.5-Flash

    Released Jul 28, 2025

    65/100
    • ECI—
    • PriceFree / Free
    • Context131K
    Full specs Remove GLM-4.5-Flash

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GLM-4.5-Flash is our pick

GLM-4.5-Flash is the better all-round choice, scoring 65/100 against GLM-4.5-Air (49). It leads on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceGLM-4.5-FlashGLM-4.5-Flash Free · GLM-4.5-Air $0.425 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGLM-4.5-Air 131,072 · GLM-4.5-Flash 131,072 tokens
  • Widest inputsSame inputsGLM-4.5-Air: Text · GLM-4.5-Flash: Text
  • Self-hostingGLM-4.5-AirPublishes downloadable weights
How the score is built
MeasureWeightGLM-4.5-AirGLM-4.5-Flash
Price50%68100
Inputs & features30%3535
Context window20%2424
Overall100%49/10065/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

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

GLM-4.5-Air vs GLM-4.5-Flash specifications side by side
SpecificationGLM-4.5-AirZ.ai (Zhipu)GLM-4.5-FlashZ.ai (Zhipu)
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.20Free (best)
Output$1.10Free (best)
Cached input$0.03—
Blended (3:1)$0.425Free (best)
Long-context rateSame rateSame rate
Price sourceOfficial Z.AI APIOfficial Z.AI API
Limits
Context window131,072 tokens131,072 tokens
Max output98,304 tokens98,304 tokens
Inputs and features
TextYesYes
ImagesNoNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesYes
Tool callingYesYes
Structured outputNoNo
Availability
WeightsOpenProprietary
API model IDglm-4.5-airglm-4.5-flash
API providers13 (best)4
ReleasedJul 28, 2025Jul 28, 2025
Knowledge cutoffApr 2025Apr 2025
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.

  • GLM-4.5-Air$4.20
  • GLM-4.5-FlashFree
04 — Questions

Which should you choose?

Which is better: GLM-4.5-Air or GLM-4.5-Flash?

GLM-4.5-Flash is the better all-round choice, scoring 65/100 against GLM-4.5-Air (49). It leads on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, GLM-4.5-Air or GLM-4.5-Flash?

GLM-4.5-Flash is cheaper at Free input / Free output per million tokens (official Z.AI API price). GLM-4.5-Air costs $0.20 input / $1.10 output per million tokens (official Z.AI API price). GLM-4.5-Flash is listed as free.

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. GLM-4.5-Air has not been scored yet and GLM-4.5-Flash has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GLM-4.5-Air and GLM-4.5-Flash yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

GLM-4.5-Air and GLM-4.5-Flash share the same 131,072-token context window. Maximum output per response: GLM-4.5-Air up to 98,304, GLM-4.5-Flash up to 98,304 tokens.

Which can read images, PDFs, audio or video?

GLM-4.5-Air accepts text; GLM-4.5-Flash accepts text. They handle the same number of input types.

Are any of these open source?

GLM-4.5-Air publishes its weights and can be self-hosted; GLM-4.5-Flash is proprietary.

Which is newer?

GLM-4.5-Air is the newest, released Jul 28, 2025. GLM-4.5-Flash came out Jul 28, 2025. Knowledge cutoff: GLM-4.5-Air Apr 2025, GLM-4.5-Flash Apr 2025.

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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