Model Comparison

GLM-5 vs GPT-5.5 InstantWhich is better in 2026?

Comparing GLM-5 and GPT-5.5 Instant across benchmarks, pricing, and capabilities.

Verdict: GLM-5 vs GPT-5.5 Instant — which is better?

GLM-5 (by Zhipu AI) and GPT-5.5 Instant (by OpenAI) 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.

On price, GLM-5 is roughly 7.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.5 Instant also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose GLM-5 if…

  • cost matters — it's about 7.3x cheaper per token
  • you need open weights you can self-host or fine-tune

Choose GPT-5.5 Instant if…

  • you process long inputs — it offers a 400,000 token context window
  • you want the most recent training data — it shipped May 2026
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GLM-5 and GPT-5.5 Instantdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GLM-5 costs less

For input processing, GLM-5 ($1.00/1M tokens) is 5.0x cheaper than GPT-5.5 Instant ($5.00/1M tokens).

For output processing, GLM-5 ($3.20/1M tokens) is 9.4x cheaper than GPT-5.5 Instant ($30.00/1M tokens).

In conclusion, GPT-5.5 Instant is more expensive than GLM-5.*

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

Lowest available price from all providers
Sun Jun 21 2026 • llm-stats.com
Zhipu AI
GLM-5
Input tokens$1.00
Output tokens$3.20
Best providerFriendliAI
OpenAI
GPT-5.5 Instant
Input tokens$5.00
Output tokens$30.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.5 Instant accepts 400,000 input tokens compared to GLM-5's 200,000 tokens. Both models can generate responses up to 128,000 tokens.

Zhipu AI
GLM-5
Input200,000 tokens
Output128,000 tokens
OpenAI
GPT-5.5 Instant
Input400,000 tokens
Output128,000 tokens
Sun Jun 21 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.5 Instant supports multimodal inputs, whereas GLM-5 does not.

GPT-5.5 Instant can handle both text and other forms of data like images, making it suitable for multimodal applications.

GLM-5

Text
Images
Audio
Video

GPT-5.5 Instant

Text
Images
Audio
Video

License

Usage and distribution terms

GLM-5 is licensed under MIT, while GPT-5.5 Instant uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

GLM-5

MIT

Open weights

GPT-5.5 Instant

Proprietary

Closed source

Release Timeline

When each model was launched

GLM-5 was released on 2026-02-11, while GPT-5.5 Instant was released on 2026-05-05.

GPT-5.5 Instant is 3 months newer than GLM-5.

GLM-5

Feb 11, 2026

4 months ago

GPT-5.5 Instant

May 5, 2026

1 months ago

2mo newer

Knowledge Cutoff

When training data ends

GPT-5.5 Instant has a documented knowledge cutoff of 2025-08-31, while GLM-5's cutoff date is not specified.

We can confirm GPT-5.5 Instant's training data extends to 2025-08-31, but cannot make a direct comparison without GLM-5's cutoff date.

GLM-5

—

GPT-5.5 Instant

Aug 2025

Provider Availability

GLM-5 is available from FriendliAI, ZAI. GPT-5.5 Instant is available from OpenAI.

GLM-5

friendli logo
FriendliAI
Input Price:Input: $1.00/1MOutput Price:Output: $3.20/1M
z logo
Unknown Organization
Input Price:Input: $1.00/1MOutput Price:Output: $3.20/1M

GPT-5.5 Instant

openai logo
OpenAI
Input Price:Input: $5.00/1MOutput Price:Output: $30.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Zhipu AI
Less expensive input tokens
Less expensive output tokens
Has open weights
OpenAI
Larger context window (400,000 tokens)
Supports multimodal inputs

Detailed Comparison

AI Model Comparison Table
Feature
Zhipu AI
GLM-5
OpenAI
GPT-5.5 Instant

FAQ

Common questions about GLM-5 vs GPT-5.5 Instant.

Which is better, GLM-5 or GPT-5.5 Instant?

GLM-5 (Zhipu AI) and GPT-5.5 Instant (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does GLM-5 compare to GPT-5.5 Instant in benchmarks?

GLM-5 scores t2-bench: 89.7%, SWE-Bench Verified: 77.8%, BrowseComp: 75.9%, MCP Atlas: 67.8%, Terminal-Bench 2.0: 56.2%. GPT-5.5 Instant scores HealthBench Consensus: 94.7%, OmniDocBench 1.5: 87.5%, GPQA: 85.6%, CharXiv-R: 81.6%, AIME 2025: 81.2%.

Is GLM-5 cheaper than GPT-5.5 Instant?

GLM-5 is 5.0x cheaper for input tokens. GLM-5 costs $1.00/M input and $3.20/M output via friendli. GPT-5.5 Instant costs $5.00/M input and $30.00/M output via openai.

What are the context window sizes for GLM-5 and GPT-5.5 Instant?

GLM-5 supports 200K tokens and GPT-5.5 Instant supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GLM-5 and GPT-5.5 Instant?

Key differences include context window (200K vs 400K), input pricing ($1.00 vs $5.00/M), multimodal support (no vs yes), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GLM-5 and GPT-5.5 Instant?

GLM-5 is developed by Zhipu AI and GPT-5.5 Instant is developed by OpenAI.

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