Compare/GLM-5.1 (Reasoning) vs o3-mini (high)

GLM-5.1 (Reasoning)vso3-mini (high)

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

Z AI

GLM-5.1 (Reasoning)

Input
$1.4/M
Output
$4.4/M
Speed
79 tok/s
TTFT
1.08s
OpenAI

o3-mini (high)

Input
$1.1/M
Output
$4.4/M
Speed
156 tok/s
TTFT
25.63s

Winner by Category

Cheaper
o3-mini (high)
Faster (tok/s)
o3-mini (high)
Lower Latency
GLM-5.1 (Reasoning)
Benchmarks (7-3)
GLM-5.1 (Reasoning)

Pricing Comparison

MetricGLM-5.1 (Reasoning)o3-mini (high)
Input ($/M tokens)$1.4$1.1
Output ($/M tokens)$4.4$4.4
Cost for 1M input + 100K output tokens:
GLM-5.1 (Reasoning)$1.84
o3-mini (high)$1.54

Speed Comparison

Output Speed (tokens/s) — higher is better
GLM-5.1 (Reasoning)
79 tok/s
o3-mini (high)
156 tok/s
Time to First Token (seconds) — lower is better
GLM-5.1 (Reasoning)
1.08s
o3-mini (high)
25.63s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
51.325.2
Coding Index
42.917.3
Math Index
GPQA Diamond
86.8%77.3%
MMLU-Pro
80.2%
LiveCodeBench
73.4%
AIME 2025
MATH-500
98.5%
Humanity's Last Exam
28.0%12.3%
SciCode
43.8%39.8%
IFBench
76.3%67.1%
TerminalBench
42.4%6.1%
GLM-5.1 (Reasoning)7 wins
3 winso3-mini (high)

Frequently Asked Questions

Which is cheaper, GLM-5.1 (Reasoning) or o3-mini (high)?

o3-mini (high) is cheaper overall. Its blended price (3:1 input/output ratio) is $1.93/M tokens vs $2.15/M for GLM-5.1 (Reasoning).

Which model performs better on benchmarks?

GLM-5.1 (Reasoning) wins 7 out of 12 benchmarks compared to 3 for o3-mini (high). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

o3-mini (high) generates tokens faster at 156 tok/s vs 79 tok/s. GLM-5.1 (Reasoning) also has lower time-to-first-token (1.08s vs 25.63s).

When should I use GLM-5.1 (Reasoning) vs o3-mini (high)?

Choose based on your priorities: o3-mini (high) for lower cost, GLM-5.1 (Reasoning) for stronger benchmark performance, and o3-mini (high) for faster generation. For latency-sensitive apps, check the TTFT comparison above.