ZMIME
Comparison · 2 models · Updated Oct 4, 2026

Gemini 3.8 Flash vs GLM-5.3-Flash

GLM-5.3-Flash comes out ahead, 80 to 75 on our weighted score, and it is the cheaper option too.

  1. 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. Our pick

    Z.ai (Zhipu)

    GLM-5.3-Flash

    Released Aug 26, 2026

    80/100
    • ECI151.9
    • Price$0.15 / $0.50
    • Context1M
    Full specs Remove GLM-5.3-Flash

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GLM-5.3-Flash is our pick

GLM-5.3-Flash is the better all-round choice, scoring 80/100 against Gemini 3.8 Flash (75). It leads on price. Gemini 3.8 Flash wins on capability 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-Flash 151.9
  • Lowest priceGLM-5.3-FlashGLM-5.3-Flash $0.237 · Gemini 3.8 Flash $1.50 per 1M tokens (3:1 blend)
  • Longest contextGemini 3.8 FlashGemini 3.8 Flash 1,048,576 · GLM-5.3-Flash 1,000,000 tokens
  • Widest inputsGemini 3.8 FlashGemini 3.8 Flash: Text, Images, PDFs, Audio, Video · GLM-5.3-Flash: Text, Images, PDFs, Video
  • Self-hostingGLM-5.3-FlashPublishes downloadable weights
How the score is built
MeasureWeightGemini 3.8 FlashGLM-5.3-Flash
CapabilityCapabilities Index (ECI)50%8781
Price25%4279
Inputs & features15%10090
Context window10%6160
Overall100%75/10080/100
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-Flash specifications side by side
SpecificationGemini 3.8 FlashGoogleGLM-5.3-FlashZ.ai (Zhipu)
Capability
Capabilities Index (ECI)156.9 (best)151.9
ECI rank#15 of 148 (best)#42 of 148
GPQA DiamondGraduate-level science questions95.4% (best)90.2%
FrontierMath Tiers 1–3Research-level mathematics68.4% (best)55.8%
OTIS Mock AIME 2024–2025Competition mathematics98.9% (best)93.9%
SimpleQA VerifiedShort factual questions69.7%—
Price per million tokens
Input$0.75$0.15 (best)
Output$3.75$0.50 (best)
Cached input$0.075$0.03 (best)
Blended (3:1)$1.50$0.237 (best)
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
ImagesYesYes
PDFsYesYes
AudioYesNo
VideoYesYes
ReasoningYeslow · medium · highYeslow · high · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryOpen
API model IDgemini-3.8-flashglm-5.3-flash
API providers2165 (best)
ReleasedSep 2, 2026Aug 26, 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-Flash$2.50
04 — Questions

Which should you choose?

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

GLM-5.3-Flash is the better all-round choice, scoring 80/100 against Gemini 3.8 Flash (75). It leads on price. Gemini 3.8 Flash wins on capability 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-Flash?

GLM-5.3-Flash is cheaper at $0.15 input / $0.50 output per million tokens (official Z.AI API price). Gemini 3.8 Flash costs $0.75 input / $3.75 output per million tokens (official Google API price). At a typical mix of three input tokens to one output token, that is $0.237 per million tokens for GLM-5.3-Flash versus $1.50 for Gemini 3.8 Flash (6.3× 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-Flash 151.9 (#42 of 148). Their confidence ranges do not overlap (154.6–160.4 vs 149.4–154.3), so the gap is a real one. On individual benchmarks: GPQA Diamond — Gemini 3.8 Flash 95.4%, GLM-5.3-Flash 90.2%; FrontierMath Tiers 1–3 — Gemini 3.8 Flash 68.4%, GLM-5.3-Flash 55.8%; OTIS Mock AIME 2024–2025 — Gemini 3.8 Flash 98.9%, GLM-5.3-Flash 93.9%.

Which is better for coding?

There are no published SWE-bench Verified results for Gemini 3.8 Flash and GLM-5.3-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-Flash. Maximum output per response: Gemini 3.8 Flash up to 65,536, GLM-5.3-Flash 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-Flash accepts text, images, PDFs and video. Gemini 3.8 Flash handles the widest range of inputs.

Are any of these open source?

GLM-5.3-Flash 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-Flash came out Aug 26, 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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