GLM-5.3 vs o3
GLM-5.3 significantly outperforms across most benchmarks. GLM-5.3 is 1.6x cheaper per token.
Zhipu AI · OpenAI · Updated for 2026
Which is better?
GLM-5.3 outperforms in 1 benchmarks (Humanity's Last Exam), while o3 is better at 0 benchmarks. GLM-5.3 significantly outperforms across most benchmarks.
On price, GLM-5.3 is roughly 1.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GLM-5.3 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current benchmark, pricing, and model metadata for 2026.
Choose GLM-5.3
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- cost matters — it's about 1.6x cheaper per token
- you process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Aug 2026
Choose o3
- you want predictable pricing at $2.00/M input and $8.00/M output
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
GLM-5.3 outperforms in 1 benchmarks (Humanity's Last Exam), while o3 is better at 0 benchmarks.
GLM-5.3 significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GLM-5.3 ($1.40/1M tokens) is 1.4x cheaper than o3 ($2.00/1M tokens).
For output processing, GLM-5.3 ($4.40/1M tokens) is 1.8x cheaper than o3 ($8.00/1M tokens).
In conclusion, o3 is more expensive than GLM-5.3.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GLM-5.3 accepts 1,000,000 input tokens compared to o3's 200,000 tokens. GLM-5.3 can generate longer responses up to 128,000 tokens, while o3 is limited to 100,000 tokens.
Input Capabilities
Supported data types and modalities
o3 supports multimodal inputs, whereas GLM-5.3 does not.
o3 can handle both text and other forms of data like images, making it suitable for multimodal applications.
GLM-5.3
o3
Release Timeline
When each model was launched
GLM-5.3 was released on 2026-08-14, while o3 was released on 2025-04-16.
GLM-5.3 is 16 months newer than o3.
Aug 14, 2026
1 weeks ago
1.3yr newerApr 16, 2025
1.4 years ago
Knowledge Cutoff
When training data ends
o3 has a documented knowledge cutoff of 2024-05-31, while GLM-5.3's cutoff date is not specified.
We can confirm o3's training data extends to 2024-05-31, but cannot make a direct comparison without GLM-5.3's cutoff date.
—
May 2024
Provider Availability
GLM-5.3 is available from ZAI. o3 is available from OpenAI.
GLM-5.3
o3
Outputs Comparison
Judge for yourself.
Run your own prompts against GLM-5.3 and o3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GLM-5.3 vs o3.