Gemini 1.5 Flash vs GLM-5.3-Flash
Comparing Gemini 1.5 Flash and GLM-5.3-Flash across benchmarks, pricing, and capabilities.
Google · Zhipu AI · Updated for 2026
Which is better?
Gemini 1.5 Flash and GLM-5.3-Flash trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
On price, GLM-5.3-Flash is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Gemini 1.5 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 benchmark, pricing, and model metadata for 2026.
Choose Gemini 1.5 Flash
- you process long inputs — it offers a 1,048,576 token context window
Choose GLM-5.3-Flash
- cost matters — it's about 1.1x cheaper per token
- you want the most recent training data — it shipped Aug 2026
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
Gemini 1.5 Flash and GLM-5.3-Flashdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 1.5 Flash ($0.15/1M tokens) costs the same as GLM-5.3-Flash ($0.15/1M tokens).
For output processing, Gemini 1.5 Flash ($0.60/1M tokens) is 1.2x more expensive than GLM-5.3-Flash ($0.50/1M tokens).
In conclusion, Gemini 1.5 Flash is more expensive than GLM-5.3-Flash.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Gemini 1.5 Flash accepts 1,048,576 input tokens compared to GLM-5.3-Flash's 1,000,000 tokens. GLM-5.3-Flash can generate longer responses up to 131,072 tokens, while Gemini 1.5 Flash is limited to 8,192 tokens.
Input Capabilities
Supported data types and modalities
Both Gemini 1.5 Flash and GLM-5.3-Flash support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Gemini 1.5 Flash
GLM-5.3-Flash
License
Usage and distribution terms
Gemini 1.5 Flash is licensed under a proprietary license, while GLM-5.3-Flash 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 1.5 Flash was released on 2024-05-01, while GLM-5.3-Flash was released on 2026-08-26.
GLM-5.3-Flash is 28 months newer than Gemini 1.5 Flash.
May 1, 2024
2.3 years ago
Aug 26, 2026
0 days ago
2.3yr newerKnowledge Cutoff
When training data ends
Gemini 1.5 Flash has a documented knowledge cutoff of 2023-11-01, while GLM-5.3-Flash's cutoff date is not specified.
We can confirm Gemini 1.5 Flash's training data extends to 2023-11-01, but cannot make a direct comparison without GLM-5.3-Flash's cutoff date.
Nov 2023
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Provider Availability
Gemini 1.5 Flash is available from Google. GLM-5.3-Flash is available from ZAI.
Gemini 1.5 Flash
GLM-5.3-Flash
Outputs Comparison
Judge for yourself.
Run your own prompts against Gemini 1.5 Flash and GLM-5.3-Flash side-by-side, then vote on the output you prefer.
FAQ
Common questions about Gemini 1.5 Flash vs GLM-5.3-Flash.