GLM 5.1vsGPT-4o (Omni)
GLM 5.1 is cheaper than GPT-4o (Omni) at $1.4/M vs $2.5/M input tokens.
| Spec | GLM 5.1 | GPT-4o (Omni) |
|---|---|---|
| Input price | $1.4/M tokens | $2.5/M tokens |
| Output price | $4.4/M tokens | $10/M tokens |
| Context window | 203K tokens | 128K tokens |
| Weights | Open | Closed |
| Free API (OpenRouter) | No | No |
| Released | Apr 2026 | May 2024 |
Our Verdict
GLM 5.1
GPT-4o (Omni)
Not enough votes to call it. On the specs, nothing separates them.
Too close to call
Reviewing agent-written code?See a Brief PR report
API pricing
Cost per 1M tokens
GLM 5.1
Input
$1.40
1.8× cheaper
Output
$4.40
2.3× cheaper
GPT-4o (Omni)
Input
$2.50
Output
$10.00
GLM 5.1 is cheaper on both: 1.8× input, 2.3× output.
Where to run it
17 hosts, cheapest first
GLM 5.115 hosts
Baidu Qianfanfp8$0.96 in$3.03 out203k99.3% upStreamLakefp8$0.97 in$3.04 out200k99.8% upDeepInfrafp4$1.05 in$3.50 out203k100% upSiliconFlowfp8$1.19 in$3.74 out205k100% upCrusoefp8$1.20 in$4.40 out203k98.5% upAtlasCloudfp8$1.26 in$3.96 out203k99.2% up
9 more hostsFewer hosts
Alibaba Cloudfp8$1.33 in$4.18 out203k100% upNovitafp8$1.38 in$4.40 out205k99.6% upFriendli$1.40 in$4.40 out203k100% upGMI Cloudfp8$1.40 in$4.40 out203k99.7% upZ.aifp8$1.40 in$4.40 out203k99.8% upVenicefp8$1.40 in$4.40 out200k99.2% upChutesfp8degraded$0.98 in$3.08 out203k89.8% upPhaladegraded$1.21 in$4.20 out203k90.2% upNebiusfp8degraded$1.40 in$4.40 out203k94% up
Per million tokens. Prices and uptime via OpenRouter, checked 13 Sep 2026.
Writing DNA
Style Comparison
Similarity
47%
GPT-4o (Omni) uses 2.5x more emoji
GLM 5.1
GPT-4o (Omni)
54%Vocabulary54%
18wSentence Length18w
0.31Hedging0.72
3.6Bold7.3
2.6Lists5.6
0.00Emoji0.03
0.43Headings1.40
0.11Transitions0.26
Based on 27 + 24 text responses
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