GPT-5.4 Mini vs GLM 5.1

GPT-5.4 Mini at $0.863 in and $5.17 out and GLM 5.1 at $1.09 in and $3.44 out — per million tokens, from the same wallet.

GPT-5.4 Mini

OpenAI

0.85¢

for a client proposal

$0.863 in · $5.17 out / 1M

400K context · released 5 months ago

Full page →

GLM 5.1

Z.ai

0.82¢

for a client proposal

$1.09 in · $3.44 out / 1M

203K context · released 4 months ago

Full page →

Asking all both at once — identical prompt, identical context — costs about 1.7¢ for a typical client proposal.

At a glance

Cheapest input: GPT-5.4 Mini at $0.863 per million tokens.
Cheapest output: GLM 5.1 at $3.44 per million tokens.
Largest context: GPT-5.4 Mini at 400K tokens — about 570 pages.

Cost per task

Estimated totals at the rates above. Solid bar is input, lighter bar is output.

Quick code fix

2K in · 500 out

GPT-5.4 Mini

0.43¢

GLM 5.1

0.39¢

Draft a client proposal from notes

5K in · 800 out

GPT-5.4 Mini

0.85¢

GLM 5.1

0.82¢

Context-heavy session (Alyph workspace)

155K in · 4K out

GPT-5.4 Mini

$0.15

GLM 5.1

$0.18

Analyze a 50-page legal contract

35K in · 1K out

GPT-5.4 Mini

3.5¢

GLM 5.1

4.2¢

Large architecture refactor

250K in · 3K out

GPT-5.4 Mini

$0.23

GLM 5.1

needs 250K ctx

Solid part of each bar is input tokens, the lighter part is output. Models that don’t fit a task are marked instead of priced.

Cost vs Token Amount

Drag the slider to adjust the split between input and output workload.

80% Input20% Output

GPT-5.4 Mini

GLM 5.1

Adjust the ratio slider to change how output tokens influence the final price for equivalent workloads.

Pricing

GPT-5.4 Mini

GLM 5.1

Input / 1M tokens

$0.863

$1.09

Output / 1M tokens

$5.17

$3.44

Cached input / 1M

$0.086

$0.203

Web search

1.1¢ / search

—

Specs

GPT-5.4 Mini

GLM 5.1

Provider

OpenAI

Z.ai

Released

5 months ago

4 months ago

Context window

400K

203K

Max output

128K

131K

Input

Files, Images, and Text

Text

Output

Text

Reasoning

Shows its thinking

Knowledge cutoff

2025-08-31

—

Try it with real numbers

2K tokens in · 500 tokens out.

GPT-5.4 Mini

OpenAI

0.43¢

for this task

40% input · 60% output

Full pricing →

GLM 5.1

Z.ai

0.39¢

for this task

56% input · 44% output

Full pricing →

All 2, same prompt and context: 0.82¢. That is the entire cost of the comparison.

Your $5 welcome credit covers about 608 of these.

Which should you pick?

For long documents, GPT-5.4 Mini has the largest context window here — 400K tokens.

On price, GLM 5.1 is the cheapest of the two on a typical task, at about 0.82¢.

For images or files, GPT-5.4 Mini can read them directly; GLM 5.1 is text-only.

Or don’t pick. Send the identical prompt to all both, read the answers side by side, and keep the winner. How to run a fair bake-off →

GPT-5.4 Mini pricing →GLM 5.1 pricing →Add Lyria 3 Clip Preview Add Grok 4.20

Questions, answered

Which is cheaper, GPT-5.4 Mini or GLM 5.1?

On a typical client proposal (5K tokens in, 800 out): GLM 5.1 at 0.82¢; GPT-5.4 Mini at 0.85¢. Long prompts can change the order when long-context rates apply.

Which has the largest context window?

GPT-5.4 Mini — 400K tokens, about 570 pages.

Can I run GPT-5.4 Mini and GLM 5.1 side by side on Alyph?

Yes — that is what Alyph is built for: the identical prompt with identical context to all 2, answers rendered side by side, billed from one wallet. This exact combination costs about 1.7¢ for a typical task.

Ask both at once

Identical prompt, identical context, answers side by side — about 1.7¢ for a typical client proposal. Free to start, with $5 of credit.