AI model comparison

GLM 4.5 vs o3 Mini

Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.

GLM-4.5 is our latest flagship foundation model, purpose-built for agent-based applications. It leverages a Mixture-of-Experts (MoE) architecture and supports a context length of up to 128k tokens.

GLM 4.5 is scheduled to be retired on December 31, 2026. Consider GLM 5.3 instead.

Input / 1M
$0.60
Output / 1M
$2.20
Context
131K
openai logo

OpenAI

o3 Mini

OpenAI o3-mini is a cost-efficient language model optimized for STEM reasoning tasks, particularly excelling in science, mathematics, and coding.

Input / 1M
$1.10
Output / 1M
$4.40
Context
200K

At a glance

Quick verdict

How the two models stack up on the things people ask about most.

Lower price

z-ai logo

GLM 4.5

1.9x cheaper for a typical chat

Higher intelligence score

z-ai logo

GLM 4.5

12.8 vs 12.5 on Artificial Analysis

Larger context window

openai logo

o3 Mini

200K vs 131K tokens

Newer release

z-ai logo

GLM 4.5

Released July 25, 2025

Benchmarks

Benchmark scores

Independent scores from Artificial Analysis. Higher is better.

Intelligence index

z-ai logoGLM 4.512.8
openai logoo3 Mini12.5

Coding index

z-ai logoGLM 4.5Not available
openai logoo3 MiniNot available

Agentic index

z-ai logoGLM 4.5Not available
openai logoo3 MiniNot available

Pricing

GLM 4.5 vs o3 Mini API pricing

Per-token API rates. Cheaper option highlighted.

Metricz-ai logoGLM 4.5openai logoo3 Mini
Input tokensPer 1M tokens$0.60$1.10
Output tokensPer 1M tokens$2.20$4.40
Cached input (read)Per 1M tokens$0.11$0.55
Cache writePer 1M tokensNot availableNot available
Web searchPer requestNot available$0.01

What it costs in practice

Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.

Chat message

2K in, 500 out

z-ai logoGLM 4.5$2.30
openai logoo3 Mini$4.40

Coding task

30K in, 4K out

z-ai logoGLM 4.5$26.80$12.10 cached
openai logoo3 Mini$50.60$34.10 cached

Long document summary

150K in, 2K out

z-ai logoGLM 4.5$94.40$20.90 cached
openai logoo3 Mini$173.80$91.30 cached

Specs

Context window and capabilities

How much each model can read, how much it can write, and what it accepts as input.

Metricz-ai logoGLM 4.5openai logoo3 Mini
Context window131K tokens200K tokens
Max output98K tokens100K tokens
Input typesTextFile, Text
Output typesTextText
Reasoning effort levelsNot availableNot available
Default reasoning effortNot availableNot available
Release dateJuly 25, 2025January 31, 2025

Features

Supported features

API features available for each model.

Metricz-ai logoGLM 4.5openai logoo3 Mini
Tool callingSupportedSupported
Structured outputsNot supportedSupported
JSON modeSupportedSupported
ReasoningSupportedSupported
TemperatureSupportedNot supported
Stop sequencesNot supportedNot supported
Deterministic seedNot supportedSupported
Verbosity controlNot supportedNot supported

Our take

GLM 4.5 is 1.9x cheaper for a typical chat. GLM 4.5 scores higher on the Artificial Analysis Intelligence Index (12.8 vs 12.5). o3 Mini has the larger context window (200K vs 131K tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.

FAQ

Frequently asked questions

Is GLM 4.5 or o3 Mini cheaper?

GLM 4.5 is cheaper for a typical chat (2K input tokens and 500 output tokens). GLM 4.5 costs $0.60 per 1M input tokens and $2.20 per 1M output tokens, while o3 Mini costs $1.10 per 1M input tokens and $4.40 per 1M output tokens.

Which has a bigger context window, GLM 4.5 or o3 Mini?

o3 Mini supports up to 200K tokens of context, compared with 131K for GLM 4.5.

Is GLM 4.5 smarter than o3 Mini?

On the Artificial Analysis Intelligence Index, GLM 4.5 scores 12.8 and o3 Mini scores 12.5, putting GLM 4.5 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.

Can I use GLM 4.5 and o3 Mini at the same time?

Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see GLM 4.5 and o3 Mini answer side by side and keep the better response.

z-ai logoopenai logo

Why choose? Ask both.

Send one prompt to GLM 4.5 and o3 Mini at the same time. Compare the answers side by side and keep the best one.