Model Comparison
GPT-5.5 Instant vs GLM-5.2Which is better in 2026?
GLM-5.2 significantly outperforms across most benchmarks. GLM-5.2 is 7.7x cheaper per token.
Verdict: GPT-5.5 Instant vs GLM-5.2 — which is better?
GPT-5.5 Instant (by OpenAI) and GLM-5.2 (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.
GPT-5.5 Instant outperforms in 0 benchmarks, while GLM-5.2 is better at 1 benchmark (GPQA). GLM-5.2 significantly outperforms across most benchmarks.
On price, GLM-5.2 is roughly 7.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GLM-5.2 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-5.5 Instant if…
- you want predictable pricing at $5.00/M input and $30.00/M output
Choose GLM-5.2 if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- cost matters — it's about 7.7x 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 Jun 2026
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.5 Instant outperforms in 0 benchmarks, while GLM-5.2 is better at 1 benchmark (GPQA).
GLM-5.2 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.5 Instant ($5.00/1M tokens) is 5.3x more expensive than GLM-5.2 ($0.95/1M tokens).
For output processing, GPT-5.5 Instant ($30.00/1M tokens) is 10.0x more expensive than GLM-5.2 ($3.00/1M tokens).
In conclusion, GPT-5.5 Instant is more expensive than GLM-5.2.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GLM-5.2 accepts 1,048,576 input tokens compared to GPT-5.5 Instant's 400,000 tokens. GLM-5.2 can generate longer responses up to 131,072 tokens, while GPT-5.5 Instant is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
GPT-5.5 Instant supports multimodal inputs, whereas GLM-5.2 does not.
GPT-5.5 Instant can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5.5 Instant
GLM-5.2
License
Usage and distribution terms
GPT-5.5 Instant is licensed under a proprietary license, while GLM-5.2 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
GPT-5.5 Instant was released on 2026-05-05, while GLM-5.2 was released on 2026-06-16.
GLM-5.2 is 1 month newer than GPT-5.5 Instant.
May 5, 2026
2 months ago
Jun 16, 2026
1 months ago
1mo newerKnowledge Cutoff
When training data ends
GPT-5.5 Instant has a documented knowledge cutoff of 2025-08-31, while GLM-5.2'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-5.2's cutoff date.
Aug 2025
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Provider Availability
GPT-5.5 Instant is available from OpenAI. GLM-5.2 is available from DeepInfra, Fireworks, FriendliAI, Novita, Together, ZAI.
GPT-5.5 Instant
GLM-5.2
Outputs Comparison
Key Takeaways
GLM-5.2
View detailsZhipu AI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-5.5 Instant and GLM-5.2 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-5.5 Instant vs GLM-5.2.