Model Comparison

Gemini 3.5 Flash vs GLM-5.1Which is better in 2026?

Gemini 3.5 Flash shows notably better performance in the majority of benchmarks. GLM-5.1 is 1.6x cheaper per token.

Verdict: Gemini 3.5 Flash vs GLM-5.1 — which is better?

Gemini 3.5 Flash (by Google) and GLM-5.1 (by Zhipu AI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Gemini 3.5 Flash outperforms in 6 benchmarks (Finance Agent v2, GDPval-AA, LiveBench, MCP Atlas, Terminal-Bench 2.0, Toolathlon), while GLM-5.1 is better at 2 benchmarks (Humanity's Last Exam, SWE-Bench Pro). Gemini 3.5 Flash shows notably better performance in the majority of benchmarks.

On price, GLM-5.1 is roughly 1.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 3.5 Flash also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 3.5 Flash if…

  • you want the strongest raw capability — it leads on 6 of 8 shared benchmarks
  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped May 2026

Choose GLM-5.1 if…

  • cost matters — it's about 1.6x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

8 benchmarks

Gemini 3.5 Flash outperforms in 6 benchmarks (Finance Agent v2, GDPval-AA, LiveBench, MCP Atlas, Terminal-Bench 2.0, Toolathlon), while GLM-5.1 is better at 2 benchmarks (Humanity's Last Exam, SWE-Bench Pro).

Gemini 3.5 Flash shows notably better performance in the majority of benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GLM-5.1 costs less

For input processing, Gemini 3.5 Flash ($1.50/1M tokens) is 1.1x more expensive than GLM-5.1 ($1.40/1M tokens).

For output processing, Gemini 3.5 Flash ($9.00/1M tokens) is 2.0x more expensive than GLM-5.1 ($4.40/1M tokens).

In conclusion, Gemini 3.5 Flash is more expensive than GLM-5.1.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Fri Jul 17 2026 • llm-stats.com
Google
Gemini 3.5 Flash
Input tokens$1.50
Output tokens$9.00
Best providerGoogle
Zhipu AI
GLM-5.1
Input tokens$1.40
Output tokens$4.40
Best providerFriendliAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 3.5 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 3.5 Flash is limited to 65,536 tokens.

Google
Gemini 3.5 Flash
Input1,048,576 tokens
Output65,536 tokens
Zhipu AI
GLM-5.1
Input200,000 tokens
Output128,000 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Gemini 3.5 Flash supports multimodal inputs, whereas GLM-5.1 does not.

Gemini 3.5 Flash can handle both text and other forms of data like images, making it suitable for multimodal applications.

Gemini 3.5 Flash

Text
Images
Audio
Video

GLM-5.1

Text
Images
Audio
Video

License

Usage and distribution terms

Gemini 3.5 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.

Gemini 3.5 Flash

Proprietary

Closed source

GLM-5.1

MIT

Open weights

Release Timeline

When each model was launched

Gemini 3.5 Flash was released on 2026-05-19, while GLM-5.1 was released on 2026-04-07.

Gemini 3.5 Flash is 1 month newer than GLM-5.1.

Gemini 3.5 Flash

May 19, 2026

1 months ago

1mo newer
GLM-5.1

Apr 7, 2026

3 months ago

Knowledge Cutoff

When training data ends

Gemini 3.5 Flash has a documented knowledge cutoff of 2026-01-31, while GLM-5.1's cutoff date is not specified.

We can confirm Gemini 3.5 Flash's training data extends to 2026-01-31, but cannot make a direct comparison without GLM-5.1's cutoff date.

Gemini 3.5 Flash

Jan 2026

GLM-5.1

—

Provider Availability

Gemini 3.5 Flash is available from Google. GLM-5.1 is available from FriendliAI, ZAI.

Gemini 3.5 Flash

google logo
Google
Input Price:Input: $1.50/1MOutput Price:Output: $9.00/1M

GLM-5.1

friendli logo
FriendliAI
Input Price:Input: $1.40/1MOutput Price:Output: $4.40/1M
z logo
Unknown Organization
Input Price:Input: $1.40/1MOutput Price:Output: $4.40/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Google
Larger context window (1,048,576 tokens)
Supports multimodal inputs
Higher Finance Agent v2 score (57.9% vs 44.8%)
Higher GDPval-AA score (45.7% vs 42.7%)
Higher LiveBench score (75.0% vs 70.2%)
Higher MCP Atlas score (83.6% vs 71.8%)
Higher Terminal-Bench 2.0 score (76.2% vs 69.0%)
Higher Toolathlon score (56.5% vs 40.7%)
Zhipu AI
Less expensive input tokens
Less expensive output tokens
Has open weights
Higher Humanity's Last Exam score (52.3% vs 40.2%)
Higher SWE-Bench Pro score (58.4% vs 55.1%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 3.5 Flash and GLM-5.1 side-by-side, then vote on the output you prefer.

Gemini 3.5 Flash
✓ Preferred
GLM-5.1
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 3.5 Flash
Zhipu AI
GLM-5.1

FAQ

Common questions about Gemini 3.5 Flash vs GLM-5.1.

Which is better, Gemini 3.5 Flash or GLM-5.1?

Gemini 3.5 Flash shows notably better performance in the majority of benchmarks. Gemini 3.5 Flash is made by Google and GLM-5.1 is made by Zhipu AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Gemini 3.5 Flash compare to GLM-5.1 in benchmarks?

Gemini 3.5 Flash scores CharXiv-R: 84.2%, MCP Atlas: 83.6%, MMMU-Pro: 83.6%, OSWorld-Verified: 78.4%, Terminal-Bench 2.0: 76.2%. GLM-5.1 scores Vending-Bench 2: 100.0%, AIME 2026: 95.3%, HMMT 2025: 94.0%, GPQA: 86.2%, IMO-AnswerBench: 83.8%.

Is Gemini 3.5 Flash cheaper than GLM-5.1?

GLM-5.1 is 1.1x cheaper for input tokens. Gemini 3.5 Flash costs $1.50/M input and $9.00/M output via google. GLM-5.1 costs $1.40/M input and $4.40/M output via friendli.

What are the context window sizes for Gemini 3.5 Flash and GLM-5.1?

Gemini 3.5 Flash supports 1.0M tokens and GLM-5.1 supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 3.5 Flash and GLM-5.1?

Key differences include context window (1.0M vs 200K), input pricing ($1.50 vs $1.40/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3.5 Flash and GLM-5.1?

Gemini 3.5 Flash is developed by Google and GLM-5.1 is developed by Zhipu AI.

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