Cheaper overall
GPT-5.4 Mini
22% lower blended rate
Bigger context window
GPT-5.4 Mini
400,000 vs 200,000 tokens
Cheaper cached input
GPT-5.4 Mini
$0.075 vs $0.26, 71% less
Where each one wins
GLM 5.1
- Cheaper output tokens $4.40 vs $4.50, 2% less
- Higher overall intelligence (Intelligence Index) 26.1 vs 24.1
- Higher multi-step tool use (Agentic Index) 23.9 vs 17.9
- Higher expert-exam performance (Humanity's Last Exam) 30.1 vs 28.1
- Ahead on 4 more benchmark figures
GPT-5.4 Mini
- Cheaper input tokens $0.75 vs $1.40, 46% less
- Cheaper cached input $0.075 vs $0.26, 71% less
- Cheaper on all four workloads
- Larger context window 400,000 tokens
- Higher coding ability (Coding Index) 56.1 vs 55.8
- Higher graduate-level science (GPQA Diamond) 87.5 vs 86.8
- Higher long-context reasoning (AA-LCR) 77 vs 73.7
- Ahead on 4 more benchmark figures
- Offers Batch and Flex pricing not listed for GLM 5.1
What four workloads cost
One run, and the same run a thousand times.
GPT-5.4 Mini is cheaper on all four workloads, by much the same margin each time โ about 1.6 times, from $0.0030 against $0.0036 on a chat turn to $0.1380 against $0.2736 on a long document.
| Workload | GLM 5.1 | GPT-5.4 Mini | ร1,000 | Difference |
|---|---|---|---|---|
| Chat turn 1,000 in / 500 out | $0.0036 | $0.0030 | $3.60 / $3.00 | GPT-5.4 Mini is 17% cheaper |
| RAG answer 10,000 in / 800 out | $0.0175 | $0.0111 | $17.52 / $11.10 | GPT-5.4 Mini is 37% cheaper |
| Agent loop 32,000 in / 700 out ร 20 calls | $0.2736 | $0.1380 | $273.60 / $138.00 | GPT-5.4 Mini is 50% cheaper |
| Long document 400,000 in / 3,000 out | GLM 5.1's context window holds 200,000 tokens, so a 400,000-token prompt does not fit. | |||
Price per 1M tokens
Neither model changes its rate with prompt length, so these rates apply to every request.
| Context band | Price | GLM 5.1 | GPT-5.4 Mini | Difference |
|---|---|---|---|---|
| Any prompt length | Input | $1.40 | $0.75 | GPT-5.4 Mini is 46% cheaper |
| Any prompt length | Cached input | $0.26 | $0.075 | GPT-5.4 Mini is 71% cheaper |
| Any prompt length | Output | $4.40 | $4.50 | GLM 5.1 is 2% cheaper |
Blended: GLM 5.1 $2.15, GPT-5.4 Mini $1.6875 per 1M โ one rate at 3:1 input to output, for comparing two models at a glance.
GLM 5.1 priced by Z.ai, GPT-5.4 Mini by OpenAI. Standard tier, pay-as-you-go.
Other pricing tiers
Only GPT-5.4 Mini lists Batch and Flex, at up to 50% off its own standard rate; GLM 5.1 offers none of them.
Every tier either model sells is here, so this is the whole price sheet. A saving is measured against that model's own standard rate โ how we read tiers.
| Tier | GLM 5.1 | GPT-5.4 Mini | Cheaper |
|---|---|---|---|
| Batch only on GPT-5.4 Mini | Not offered | $0.375 in / $2.25 out 50% off Standard | — |
| Flex only on GPT-5.4 Mini | Not offered | $0.375 in / $2.25 out 50% off Standard | — |
Benchmarks
They share 14 figures: GLM 5.1 leads on 7, GPT-5.4 Mini on 7. The widest gap is 59.9 points, on answer reliability (Omniscience Non-Hallucination).
Overall intelligence
Intelligence Index โ Overall intelligence across reasoning, knowledge & math evals
GLM 5.1 ahead by 2
Coding ability
Coding Index โ Coding ability across software-engineering evals
GPT-5.4 Mini ahead by 0.3
Multi-step tool use
Agentic Index โ Tool use & multi-step agent task performance
GLM 5.1 ahead by 6
Graduate-level science
GPQA Diamond โ Graduate-level questions in biology, chemistry & physics
GPT-5.4 Mini ahead by 0.7
Expert-exam performance
Humanity's Last Exam โ Expert-level questions across many academic domains
GLM 5.1 ahead by 2
Instruction following
IFBench โ Precise following of detailed instructions
GLM 5.1 ahead by 3
Support-agent performance
ฯยฒ-Bench Telecom โ Tool-using agent tasks in a telecom support setting
GLM 5.1 ahead by 14.4
Long-context reasoning
AA-LCR โ Long-context reasoning across large inputs
GPT-5.4 Mini ahead by 3.3
Scientific coding
SciCode โ Research-level scientific coding tasks
GPT-5.4 Mini ahead by 7.3
Command-line work
Terminal-Bench Hard โ Complex command-line and terminal workflows
GPT-5.4 Mini ahead by 9.1
Physics research reasoning
CritPt โ Unpublished physics research reasoning problems
GPT-5.4 Mini ahead by 5.4
Real-world task performance
GDPval โ Economically valuable, real-world knowledge work
GLM 5.1 ahead by 5.2
Factual accuracy
Omniscience Accuracy โ Breadth of factual knowledge across domains
GPT-5.4 Mini ahead by 12.3
Answer reliability
Omniscience Non-Hallucination โ How reliably the model avoids fabricated answers
GLM 5.1 ahead by 59.9
Each figure is that model's best published run, with the effort level named beside it โ where these scores come from.
Specifications
GPT-5.4 Mini holds 200,000 more input tokens in one request. GPT-5.4 Mini also takes file and image.
| Specification | GLM 5.1 | GPT-5.4 Mini |
|---|---|---|
| Context window | 200,000 tokens | 400,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Takes in | Text | Text, image, file |
| Puts out | Text | Text |
| Knowledge cutoff | โ | 31 Aug 2025 |
| Released | 7 Apr 2026 | 17 Mar 2026 |
| Status | Active | Active |
| Sold by | Z.ai | OpenAI, Perplexity |
FAQs
- Is GLM 5.1 cheaper than GPT-5.4 Mini?
- No โ the other way round. A 1,000-token prompt with a 500-token reply costs $0.0036 on GLM 5.1 and $0.0030 on GPT-5.4 Mini, and the same model is cheaper on every workload on this page.
- How much do GLM 5.1 and GPT-5.4 Mini cost per 1M tokens?
- GLM 5.1 costs $1.40 for input and $4.40 for output. GPT-5.4 Mini costs $0.75 and $4.50. Standard pay-as-you-go rates, as of 7 Apr 2026.
- Which is better, GLM 5.1 or GPT-5.4 Mini?
- On published benchmarks, GLM 5.1. It leads on 7 of the 14 figures both models report, including overall intelligence (Intelligence Index), where it scores 26.1 against 24.1.
- Does GLM 5.1 or GPT-5.4 Mini offer batch pricing?
- GPT-5.4 Mini only. Its batch input costs $0.375, 50% off its standard rate, and GLM 5.1 lists no batch tier at all.
- Does GLM 5.1 or GPT-5.4 Mini have a bigger context window?
- GPT-5.4 Mini, at 400,000 tokens against 200,000. That is 200,000 more input tokens in a single request.