ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GLM-5.3 vs Gemini 3.8 Flash

Gemini 3.8 Flash comes out ahead, 75 to 64 on our weighted score, and it is the cheaper option too.

  1. Z.ai (Zhipu)

    GLM-5.3

    Released Aug 14, 2026

    64/100
    • ECI155.8
    • Price$1.40 / $4.40
    • Context1M
    Full specs Remove GLM-5.3
  2. Our pick

    Google

    Gemini 3.8 Flash

    Released Sep 2, 2026

    75/100
    • ECI156.9
    • Price$0.75 / $3.75
    • Context1.05M
    Full specs Remove Gemini 3.8 Flash

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Gemini 3.8 Flash is our pick

Gemini 3.8 Flash is the better all-round choice, scoring 75/100 against GLM-5.3 (64). It leads on price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGemini 3.8 FlashCapabilities Index (ECI): Gemini 3.8 Flash 156.9 · GLM-5.3 155.8
  • Lowest priceGemini 3.8 FlashGemini 3.8 Flash $1.50 · GLM-5.3 $2.15 per 1M tokens (3:1 blend)
  • Longest contextGemini 3.8 FlashGemini 3.8 Flash 1,048,576 · GLM-5.3 1,000,000 tokens
  • Widest inputsGemini 3.8 FlashGLM-5.3: Text · Gemini 3.8 Flash: Text, Images, PDFs, Audio, Video
  • Self-hostingGLM-5.3Publishes downloadable weights
How the score is built
MeasureWeightGLM-5.3Gemini 3.8 Flash
CapabilityCapabilities Index (ECI)50%8587
Price25%3442
Inputs & features15%45100
Context window10%6061
Overall100%64/10075/100
02 — Side by side

Every spec in one table

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

GLM-5.3 vs Gemini 3.8 Flash specifications side by side
SpecificationGLM-5.3Z.ai (Zhipu)Gemini 3.8 FlashGoogle
Capability
Capabilities Index (ECI)155.8156.9 (best)
ECI rank#24 of 148#15 of 148 (best)
GPQA DiamondGraduate-level science questions90.9%95.4% (best)
FrontierMath Tiers 1–3Research-level mathematics68.8% (best)68.4%
OTIS Mock AIME 2024–2025Competition mathematics91.1%98.9% (best)
SimpleQA VerifiedShort factual questions41.0%69.7% (best)
Price per million tokens
Input$1.40$0.75 (best)
Output$4.40$3.75 (best)
Cached input$0.26$0.075 (best)
Blended (3:1)$2.15$1.50 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Z.AI APIOfficial Google API
Limits
Context window1,000,000 tokens1,048,576 tokens (best)
Max output131,072 tokens (best)65,536 tokens
Inputs and features
TextYesYes
ImagesNoYes
PDFsNoYes
AudioNoYes
VideoNoYes
ReasoningYeslow · high · maxYeslow · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsOpenProprietary
API model IDglm-5.3gemini-3.8-flash
API providers62 (best)21
ReleasedAug 14, 2026Sep 2, 2026
Knowledge cutoff——
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-5.3$22.80
  • Gemini 3.8 Flash$15.00
04 — Questions

Which should you choose?

Which is better: GLM-5.3 or Gemini 3.8 Flash?

Gemini 3.8 Flash is the better all-round choice, scoring 75/100 against GLM-5.3 (64). It leads on price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GLM-5.3 or Gemini 3.8 Flash?

Gemini 3.8 Flash is cheaper at $0.75 input / $3.75 output per million tokens (official Google API price). GLM-5.3 costs $1.40 input / $4.40 output per million tokens (official Z.AI API price). At a typical mix of three input tokens to one output token, that is $1.50 per million tokens for Gemini 3.8 Flash versus $2.15 for GLM-5.3 (1.4× as much).

Which scores higher on benchmarks?

Gemini 3.8 Flash scores higher on the Capabilities Index (ECI): Gemini 3.8 Flash 156.9 (#15 of 148) and GLM-5.3 155.8 (#24 of 148). The confidence ranges of the top two overlap (154.6–160.4 vs 153.7–158.3), so treat the gap as small. On individual benchmarks: GPQA Diamond — Gemini 3.8 Flash 95.4%, GLM-5.3 90.9%; FrontierMath Tiers 1–3 — GLM-5.3 68.8%, Gemini 3.8 Flash 68.4%; OTIS Mock AIME 2024–2025 — Gemini 3.8 Flash 98.9%, GLM-5.3 91.1%; SimpleQA Verified — Gemini 3.8 Flash 69.7%, GLM-5.3 41.0%.

Which is better for coding?

There are no published SWE-bench Verified results for GLM-5.3 and Gemini 3.8 Flash yet, so there is no like-for-like coding score. On overall capability, Gemini 3.8 Flash 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?

Gemini 3.8 Flash has the largest context window at 1,048,576 tokens, against 1,000,000 for GLM-5.3. Maximum output per response: GLM-5.3 up to 131,072, Gemini 3.8 Flash up to 65,536 tokens.

Which can read images, PDFs, audio or video?

GLM-5.3 accepts text; Gemini 3.8 Flash accepts text, images, PDFs, audio and video. Gemini 3.8 Flash handles the widest range of inputs.

Are any of these open source?

GLM-5.3 publishes its weights and can be self-hosted; Gemini 3.8 Flash is proprietary.

Which is newer?

Gemini 3.8 Flash is the newest, released Sep 2, 2026. GLM-5.3 came out Aug 14, 2026.

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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