ZMIME
Comparison · 2 models · Updated Oct 4, 2026

Gemini 3.8 Flash vs GLM-5.3

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

  1. 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

  2. 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

  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 FlashGemini 3.8 Flash: Text, Images, PDFs, Audio, Video · GLM-5.3: Text
  • Self-hostingGLM-5.3Publishes downloadable weights
How the score is built
MeasureWeightGemini 3.8 FlashGLM-5.3
CapabilityCapabilities Index (ECI)50%8785
Price25%4234
Inputs & features15%10045
Context window10%6160
Overall100%75/10064/100
02 — Side by side

Every spec in one table

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

Gemini 3.8 Flash vs GLM-5.3 specifications side by side
SpecificationGemini 3.8 FlashGoogleGLM-5.3Z.ai (Zhipu)
Capability
Capabilities Index (ECI)156.9 (best)155.8
ECI rank#15 of 148 (best)#24 of 148
GPQA DiamondGraduate-level science questions95.4% (best)90.9%
FrontierMath Tiers 1–3Research-level mathematics68.4%68.8% (best)
OTIS Mock AIME 2024–2025Competition mathematics98.9% (best)91.1%
SimpleQA VerifiedShort factual questions69.7% (best)41.0%
Price per million tokens
Input$0.75 (best)$1.40
Output$3.75 (best)$4.40
Cached input$0.075 (best)$0.26
Blended (3:1)$1.50 (best)$2.15
Long-context rateSame rateSame rate
Price sourceOfficial Google APIOfficial Z.AI API
Limits
Context window1,048,576 tokens (best)1,000,000 tokens
Max output65,536 tokens131,072 tokens (best)
Inputs and features
TextYesYes
ImagesYesNo
PDFsYesNo
AudioYesNo
VideoYesNo
ReasoningYeslow · medium · highYeslow · high · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryOpen
API model IDgemini-3.8-flashglm-5.3
API providers2162 (best)
ReleasedSep 2, 2026Aug 14, 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.

  • Gemini 3.8 Flash$15.00
  • GLM-5.3$22.80
04 — Questions

Which should you choose?

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

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, Gemini 3.8 Flash or GLM-5.3?

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 Gemini 3.8 Flash and GLM-5.3 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: Gemini 3.8 Flash up to 65,536, GLM-5.3 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Gemini 3.8 Flash accepts text, images, PDFs, audio and video; GLM-5.3 accepts text. 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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