How much does GLM-5.1 cost?

GLM-5.1 costs $1.40 per million input tokens and $4.40 per million output tokens, using the list price from Zai as of 26 Oct 2026. That is about $0.36 for 100 chats of about 1,000 tokens in and 500 tokens back. Confirm on the maker's site before you buy, because prices change.

What is the context window of GLM-5.1?

GLM-5.1 has a context window of 200K tokens, roughly 150,000 words of text read at once. A single answer can be up to 128K tokens long.

Is GLM-5.1 open source?

GLM-5.1 has open weights: its trained parameters can be downloaded. That is not always the same as open source, because licence terms differ, so read the licence before you use it commercially.

How good is GLM-5.1 compared with other AI models?

On the Epoch Capabilities Index, GLM-5.1 scores 149.8 (likely range 147.7 to 151.9), which ranks 62 of 270 models we track. On Arena's human-vote text board it is ranked 46 of 166. Scores close together are a tie in practice.

How does GLM-5.1 compare with GPT-5.1?

GLM-5.1 scores higher on 6 of 9 shared quality measures, GPT-5.1 on 1. 2 measures are too close to call. GLM-5.1 costs about 37% less than GPT-5.1 on a blended price of $2.15 against $3.44 per million tokens. See the full comparison for every measure.

How current are these numbers for GLM-5.1?

The newest data on this page is dated 26 Oct 2026. Scores come from Epoch AI and Arena, prices from the open LiteLLM price list.

AI Rankings

GLM-5.1: Score, Price and Context Window

Where GLM-5.1 from Z.ai ranks, what it costs and how much text it can read, in plain numbers with the sources.

Data updated 26 Oct 2026

Z.ai
Open weights
Released Apr 2026

Its score range overlaps with GPT-5, the model just above it, so a small gap in rank is not a meaningful difference.

Best for

Running it yourself: its weights can be downloaded (read the licence terms first).

These lines are worked out from the numbers on this page, not from hands-on testing.

Key facts

Overall score: 149.8; Rank 62 of 270. Likely range 147.7 to 151.9.
Human preference: chat: 1465; Rank 46 of 166. 65,402 votes.
Human preference: coding: 1513; Rank 45 of 166. 17,686 votes.
Human preference: web pages: 1508; Rank 46 of 85. 10,703 votes.
Price per million tokens: $1.40 in / $4.40 out; Blended $2.15. Cached input $0.26. List price from Zai, checked 26 Oct 2026.
Context window: 200K tokens; About 150,000 words at once. One answer up to 128K tokens.
Weights: Open; The weights can be downloaded. Check the licence before commercial use.

Features listed by the price list: Tool use, Reasoning, Prompt caching.

How GLM-5.1 stacks up

Each strip shows every model we track as faint bars. The dot is this model. Better is always to the right, even for price.

GLM-5.1 compared with all models we trackOverall capability: 149.8. Better than 77% of the other 269 models. Human preference: chat: 1465. Better than 72% of the other 165 models. Human preference: coding: 1513. Better than 73% of the other 165 models. Human preference: web pages: 1508. Better than 46% of the other 84 models. Price: $2.15 per 1M. Cheaper than 34% of the other 200 priced models. Context window: 200K tokens. Larger context window than 39% of the other 198 models.

Overall capability149.8
Better than 77% of the other 269 modelsTop 25%
Epoch Capabilities Index: one score that combines many tests.
Human preference: chat1465
Better than 72% of the other 165 modelsUpper half
How often people pick its answers over another model's on Arena.
Human preference: coding1513
Better than 73% of the other 165 modelsUpper half
How often people pick its answers to coding questions on Arena.
Human preference: web pages1508
Better than 46% of the other 84 models
How often people pick the web pages and small apps it builds on Arena.
Price$2.15 per 1M
Cheaper than 34% of the other 200 priced models
Blended price per million tokens. Lower is better, so the cheapest models sit on the right.
Context window200K tokens
Larger context window than 39% of the other 198 models
How much text it can read at once. Bigger suits long documents.

Compared with the other published models that have each measure. Data updated 26 Oct 2026.

Where GLM-5.1 ranks

Leaderboards it appears on, best placing first.

See all leaderboards

Test results

Each test checks one kind of skill. Place shows where it stands among the models that took that test.

GPQA Diamond
Very hard multiple-choice science questions in biology, physics and chemistry, written by experts and designed so a quick web search does not give the answer.
89.9%
Place 42 of 183
OTIS Mock AIME
Maths competition problems in the style of the US AIME exam, from the 2024 and 2025 sets. Every answer is a whole number.
93.3%
Place 47 of 174
tied with 3 others
SimpleBench
Everyday common-sense and trick questions that most people answer correctly but AI models often get wrong.
55.1%
Place 32 of 80
SWE-bench Verified
Real bug reports from open-source software projects. The AI has to change the code so the project's own tests pass. The tasks were checked by people.
74.2%
Place 16 of 32
SimpleQA Verified
Short factual questions that each have one correct answer. It measures how often a model gets facts right.
34.0%
Place 56 of 82
FrontierMath (Tiers 1-3)
Original, very hard maths problems written by mathematicians. Each has an exact answer and the problems are kept private so models cannot have memorised them. This is the Tiers 1 to 3 set, version 2.
36.8%
Place 60 of 87

What it costs in everyday terms

List prices turned into amounts you can picture. Real bills depend on how you use it.

100 chats: $0.36; Cost of 100 chats assumes each chat sends 1,000 tokens (about 750 words) and gets 500 tokens (about 375 words) back.
A 300-page book: $0.14; Cost to read a 300-page book assumes about 100,000 input tokens and no reply. A real book varies with page size and language.
Blended price: $2.15 per 1M; Three parts input to one part output. Our own calculation for comparing models.

Similar models

Models from other makers with a similar overall score.

Learn more

Questions about GLM-5.1

How much does GLM-5.1 cost?: GLM-5.1 costs $1.40 per million input tokens and $4.40 per million output tokens, using the list price from Zai as of 26 Oct 2026. That is about $0.36 for 100 chats of about 1,000 tokens in and 500 tokens back. Confirm on the maker's site before you buy, because prices change.
What is the context window of GLM-5.1?: GLM-5.1 has a context window of 200K tokens, roughly 150,000 words of text read at once. A single answer can be up to 128K tokens long.
Is GLM-5.1 open source?: GLM-5.1 has open weights: its trained parameters can be downloaded. That is not always the same as open source, because licence terms differ, so read the licence before you use it commercially.
How good is GLM-5.1 compared with other AI models?: On the Epoch Capabilities Index, GLM-5.1 scores 149.8 (likely range 147.7 to 151.9), which ranks 62 of 270 models we track. On Arena's human-vote text board it is ranked 46 of 166. Scores close together are a tie in practice.
How does GLM-5.1 compare with GPT-5.1?: GLM-5.1 scores higher on 6 of 9 shared quality measures, GPT-5.1 on 1. 2 measures are too close to call. GLM-5.1 costs about 37% less than GPT-5.1 on a blended price of $2.15 against $3.44 per million tokens. See the full comparison for every measure.
How current are these numbers for GLM-5.1?: The newest data on this page is dated 26 Oct 2026. Scores come from Epoch AI and Arena, prices from the open LiteLLM price list.

Where this data comes from

Epoch AI: Benchmark data: Epoch AI, 'Capabilities & benchmarking', epoch.ai/benchmarks (CC BY 4.0). We match models across sources, rank them and show them in charts. Scores are not changed. Epoch AI does not endorse this site.
Arena (formerly LMArena): Human-preference ratings: Arena (arena.ai) leaderboard dataset, CC BY 4.0. We keep the latest published ratings, match them to models from other sources and rank them. Ratings are not changed. Arena does not endorse this site.
LiteLLM model price list: Prices and context windows: LiteLLM model price list (github.com/BerriAI/litellm, MIT licence). We use the model maker's own price entry when there is one. Prices change often, so always confirm on the maker's site before you buy.

Newest data on this page: 26 Oct 2026. Prices are list prices and change often, so confirm on the maker's site before you buy. Sponsors never change a score or an order. How we calculate this · Report a mistake