Gemini 3.8 Flash vs GLM-5.1
Gemini 3.8 Flash leads the LLM Stats Score 51.0 to 39.4. Gemini 3.8 Flash is 1.4x cheaper per token.
Google · Zhipu AI · Updated for 2026
Which is better?
Gemini 3.8 Flash leads the overall LLM Stats Score 51.0 to 39.4, ranking #15 overall.
On price, Gemini 3.8 Flash is roughly 1.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Gemini 3.8 Flash also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Gemini 3.8 Flash
- overall performance matters — it scores 51.0 and ranks #15 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- cost matters — it's about 1.4x cheaper per token
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Sep 2026
Choose GLM-5.1
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
13 reported for Gemini 3.8 Flash · 18 for GLM-5.1
Gemini 3.8 Flash and GLM-5.1don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 3.8 Flash ($0.75/1M tokens) is 1.9x cheaper than GLM-5.1 ($1.40/1M tokens).
For output processing, Gemini 3.8 Flash ($3.75/1M tokens) is 1.2x cheaper than GLM-5.1 ($4.40/1M tokens).
In conclusion, GLM-5.1 is more expensive than Gemini 3.8 Flash.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Gemini 3.8 Flash accepts 1,048,576 input tokens compared to GLM-5.1's 200,000 tokens. GLM-5.1 can generate longer responses up to 128,000 tokens, while Gemini 3.8 Flash is limited to 65,536 tokens.
Input capabilities
Documented input modalities across available providers
Gemini 3.8 Flash supports multimodal inputs, whereas GLM-5.1 does not.
Gemini 3.8 Flash can handle both text and other forms of data like images, making it suitable for multimodal applications.
Gemini 3.8 Flash
GLM-5.1
License
Usage and distribution terms
Gemini 3.8 Flash is licensed under a proprietary license, while GLM-5.1 uses MIT.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
Gemini 3.8 Flash was released on 2026-09-02, while GLM-5.1 was released on 2026-04-07.
Gemini 3.8 Flash is 5 months newer than GLM-5.1.
Sep 2, 2026
3 days ago
4mo newerApr 7, 2026
5 months ago
Knowledge Cutoff
When training data ends
Gemini 3.8 Flash has a documented knowledge cutoff of 2026-03-31, while GLM-5.1's cutoff date is not specified.
We can confirm Gemini 3.8 Flash's training data extends to 2026-03-31, but cannot make a direct comparison without GLM-5.1's cutoff date.
Mar 2026
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Provider Availability
Gemini 3.8 Flash is available from Google. GLM-5.1 is available from FriendliAI, ZAI.
Gemini 3.8 Flash
GLM-5.1
Outputs Comparison
Judge for yourself.
Run your own prompts against Gemini 3.8 Flash and GLM-5.1 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Gemini 3.8 Flash vs GLM-5.1.