ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GLM-4.5-Air vs Seed 1.6 Flash

Seed 1.6 Flash comes out ahead, 78 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

    ByteDance Seed

    Seed 1.6 Flash

    Released Aug 28, 2025

    78/100
    • ECI—
    • Price$0.022 / $0.223
    • Context256K
    Full specs Remove Seed 1.6 Flash

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Seed 1.6 Flash is our pick

Seed 1.6 Flash is the better all-round choice, scoring 78/100 against GLM-4.5-Air (49). It leads on price, inputs & features and context window. 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 priceSeed 1.6 FlashSeed 1.6 Flash $0.072 · GLM-4.5-Air $0.425 per 1M tokens (3:1 blend)
  • Longest contextSeed 1.6 FlashSeed 1.6 Flash 256,000 · GLM-4.5-Air 131,072 tokens
  • Widest inputsSeed 1.6 FlashGLM-4.5-Air: Text · Seed 1.6 Flash: Text, Images
  • Self-hostingGLM-4.5-AirPublishes downloadable weights
How the score is built
MeasureWeightGLM-4.5-AirSeed 1.6 Flash
Price50%68100
Inputs & features30%3570
Context window20%2436
Overall100%49/10078/100

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 Seed 1.6 Flash specifications side by side
SpecificationGLM-4.5-AirZ.ai (Zhipu)Seed 1.6 FlashByteDance Seed
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.20$0.022 (best)
Output$1.10$0.223 (best)
Cached input$0.03$0.0044 (best)
Blended (3:1)$0.425$0.072 (best)
Long-context rateSame rateOver 32K: $0.045 / $0.445
Price sourceOfficial Z.AI APIOfficial Volcengine Ark API
Limits
Context window131,072 tokens256,000 tokens (best)
Max output98,304 tokens (best)32,000 tokens
Inputs and features
TextYesYes
ImagesNoYes
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesYes
Tool callingYesYes
Structured outputNoYes
Availability
WeightsOpenProprietary
API model IDglm-4.5-airdoubao-seed-1-6-flash-250828
API providers13 (best)2
ReleasedJul 28, 2025Aug 28, 2025
Knowledge cutoffApr 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
  • Seed 1.6 Flash$0.668
04 — Questions

Which should you choose?

Which is better: GLM-4.5-Air or Seed 1.6 Flash?

Seed 1.6 Flash is the better all-round choice, scoring 78/100 against GLM-4.5-Air (49). It leads on price, inputs & features and context window. 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 Seed 1.6 Flash?

Seed 1.6 Flash is cheaper at $0.022 input / $0.223 output per million tokens (official Volcengine Ark API price). GLM-4.5-Air costs $0.20 input / $1.10 output per million tokens (official Z.AI API price). At a typical mix of three input tokens to one output token, that is $0.072 per million tokens for Seed 1.6 Flash versus $0.425 for GLM-4.5-Air (5.9× as much).

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 Seed 1.6 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 Seed 1.6 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?

Seed 1.6 Flash has the largest context window at 256,000 tokens, against 131,072 for GLM-4.5-Air. Maximum output per response: GLM-4.5-Air up to 98,304, Seed 1.6 Flash up to 32,000 tokens.

Which can read images, PDFs, audio or video?

GLM-4.5-Air accepts text; Seed 1.6 Flash accepts text and images. Seed 1.6 Flash handles the widest range of inputs.

Are any of these open source?

GLM-4.5-Air publishes its weights and can be self-hosted; Seed 1.6 Flash is proprietary.

Which is newer?

Seed 1.6 Flash is the newest, released Aug 28, 2025. GLM-4.5-Air came out Jul 28, 2025. Knowledge cutoff: GLM-4.5-Air 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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