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GLM-5.3 vs GPT-5.1 Codex

Comparing GLM-5.3 and GPT-5.1 Codex across benchmarks, pricing, and capabilities.

Zhipu AI · OpenAI · Updated for 2026

Which is better?

GLM-5.3 and GPT-5.1 Codex trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

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

  • 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 GPT-5.1 Codex

  • you want predictable pricing at $1.25/M input and $10.00/M output

At a glance

The differences that matter most.

GLM-5.3
Zhipu AI
GPT-5.1 Codex
OpenAI
Benchmark wins
—
—
Input price
$1.40 / M
$1.25 / M
Output price
$4.40 / M
$10.00 / M
Context window
1,000,000
400,000
Released
Aug 2026
Nov 2025
License
Unknown
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GLM-5.3 and GPT-5.1 Codexdon'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

GLM-5.3 costs less

For input processing, GLM-5.3 ($1.40/1M tokens) is 1.1x more expensive than GPT-5.1 Codex ($1.25/1M tokens).

For output processing, GLM-5.3 ($4.40/1M tokens) is 2.3x cheaper than GPT-5.1 Codex ($10.00/1M tokens).

In conclusion, GPT-5.1 Codex is more expensive than GLM-5.3.*

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

Lowest available price from all providers
Mon Aug 24 2026 • llm-stats.com
Zhipu AI
GLM-5.3
Input tokens$1.40
Output tokens$4.40
Best providerUnknown Organization
OpenAI
GPT-5.1 Codex
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GLM-5.3 accepts 1,000,000 input tokens compared to GPT-5.1 Codex's 400,000 tokens. Both models can generate responses up to 128,000 tokens.

Zhipu AI
GLM-5.3
Input1,000,000 tokens
Output128,000 tokens
OpenAI
GPT-5.1 Codex
Input400,000 tokens
Output128,000 tokens
Mon Aug 24 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.1 Codex supports multimodal inputs, whereas GLM-5.3 does not.

GPT-5.1 Codex can handle both text and other forms of data like images, making it suitable for multimodal applications.

GLM-5.3

Text
Images
Audio
Video

GPT-5.1 Codex

Text
Images
Audio
Video

Release Timeline

When each model was launched

GLM-5.3 was released on 2026-08-14, while GPT-5.1 Codex was released on 2025-11-19.

GLM-5.3 is 9 months newer than GPT-5.1 Codex.

GLM-5.3

Aug 14, 2026

1 weeks ago

8mo newer
GPT-5.1 Codex

Nov 19, 2025

9 months ago

Knowledge Cutoff

When training data ends

GPT-5.1 Codex has a documented knowledge cutoff of 2024-09-30, while GLM-5.3's cutoff date is not specified.

We can confirm GPT-5.1 Codex's training data extends to 2024-09-30, but cannot make a direct comparison without GLM-5.3's cutoff date.

GLM-5.3

—

GPT-5.1 Codex

Sep 2024

Provider Availability

GLM-5.3 is available from ZAI. GPT-5.1 Codex is available from OpenAI.

GLM-5.3

z logo
Unknown Organization
Input Price:Input: $1.40/1MOutput Price:Output: $4.40/1M

GPT-5.1 Codex

openai logo
OpenAI
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against GLM-5.3 and GPT-5.1 Codex side-by-side, then vote on the output you prefer.

GLM-5.3
✓ Preferred
GPT-5.1 Codex
Open in Playground

FAQ

Common questions about GLM-5.3 vs GPT-5.1 Codex.

Which is better, GLM-5.3 or GPT-5.1 Codex?

GLM-5.3 (Zhipu AI) and GPT-5.1 Codex (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-5.3 compare to GPT-5.1 Codex in benchmarks?

GLM-5.3 scores Terminal-Bench 2.1: 88.2%, CyberGym: 84.5%, FrontierSWE: 78.1%, Toolathlon: 73.0%, DeepSWE 1.1: 66.9%. GPT-5.1 Codex scores SWE-Bench Verified: 73.7%, SWE-Lancer: 66.3%, Terminal-Bench 2.0: 52.8%.

Is GLM-5.3 cheaper than GPT-5.1 Codex?

GPT-5.1 Codex is 1.1x cheaper for input tokens. GLM-5.3 costs $1.40/M input and $4.40/M output via z. GPT-5.1 Codex costs $1.25/M input and $10.00/M output via openai.

What are the context window sizes for GLM-5.3 and GPT-5.1 Codex?

GLM-5.3 supports 1.0M tokens and GPT-5.1 Codex 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-5.3 and GPT-5.1 Codex?

Key differences include context window (1.0M vs 400K), input pricing ($1.40 vs $1.25/M), multimodal support (no vs yes), licensing (Unknown vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GLM-5.3 and GPT-5.1 Codex?

GLM-5.3 is developed by Zhipu AI and GPT-5.1 Codex is developed by OpenAI.

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