The AI arena is free today

Open Superagent

Claude Mythos Preview vs GLM-5.3

Both models are evenly matched across the benchmarks. GLM-5.3 is 23.3x cheaper per token.

Anthropic · Zhipu AI · Updated for 2026

Which is better?

Claude Mythos Preview outperforms in 1 benchmarks (Humanity's Last Exam), while GLM-5.3 is better at 1 benchmark (CyberGym). Both models are evenly matched across the benchmarks.

On price, GLM-5.3 is roughly 23.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Based on current benchmark, pricing, and model metadata for 2026.

Choose Claude Mythos Preview

  • you want predictable pricing at $25.00/M input and $125.00/M output

Choose GLM-5.3

  • cost matters — it's about 23.3x cheaper per token

At a glance

The differences that matter most.

Claude Mythos Preview
Anthropic
GLM-5.3
Zhipu AI
Benchmark wins
1 of 2
1 of 2
Input price
$25.00 / M
$1.40 / M
Output price
$125.00 / M
$4.40 / M
Context window
—
1,000,000
Released
—
Aug 2026
License
Proprietary
Unknown

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Mythos Preview outperforms in 1 benchmarks (Humanity's Last Exam), while GLM-5.3 is better at 1 benchmark (CyberGym).

Both models are evenly matched across the benchmarks.

Tue Aug 25 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Pricing Analysis

Price comparison per million tokens

GLM-5.3 costs less

For input processing, Claude Mythos Preview ($25.00/1M tokens) is 17.9x more expensive than GLM-5.3 ($1.40/1M tokens).

For output processing, Claude Mythos Preview ($125.00/1M tokens) is 28.4x more expensive than GLM-5.3 ($4.40/1M tokens).

In conclusion, Claude Mythos Preview is more expensive than GLM-5.3.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Aug 25 2026 • llm-stats.com
Anthropic
Claude Mythos Preview
Input tokens$25.00
Output tokens$125.00
Best providerAnthropic
Zhipu AI
GLM-5.3
Input tokens$1.40
Output tokens$4.40
Best providerUnknown Organization
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Only GLM-5.3 specifies input context (1,000,000 tokens). Only GLM-5.3 specifies output context (128,000 tokens).

Anthropic
Claude Mythos Preview
Input- tokens
Output- tokens
Zhipu AI
GLM-5.3
Input1,000,000 tokens
Output128,000 tokens
Tue Aug 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Mythos Preview supports multimodal inputs, whereas GLM-5.3 does not.

Claude Mythos Preview can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Mythos Preview

Text
Images
Audio
Video

GLM-5.3

Text
Images
Audio
Video

Release Timeline

When each model was launched

GLM-5.3 was released on 2026-08-14, while Claude Mythos Preview's release date is not specified.

We can confirm GLM-5.3's release timeline, but cannot make a direct age comparison without Claude Mythos Preview's release date.

Claude Mythos Preview

—

GLM-5.3

Aug 14, 2026

1 weeks ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Mythos Preview is available from Anthropic. GLM-5.3 is available from ZAI.

Claude Mythos Preview

anthropic logo
Anthropic
Input Price:Input: $25.00/1MOutput Price:Output: $125.00/1M

GLM-5.3

z logo
Unknown Organization
Input Price:Input: $1.40/1MOutput Price:Output: $4.40/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Mythos Preview and GLM-5.3 side-by-side, then vote on the output you prefer.

Claude Mythos Preview
✓ Preferred
GLM-5.3
Open in Playground

FAQ

Common questions about Claude Mythos Preview vs GLM-5.3.

Which is better, Claude Mythos Preview or GLM-5.3?

Both models are evenly matched across the benchmarks. Claude Mythos Preview is made by Anthropic and GLM-5.3 is made by Zhipu AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Mythos Preview compare to GLM-5.3 in benchmarks?

Claude Mythos Preview scores CyBench: 100.0%, USAMO25: 97.6%, GPQA: 94.6%, SWE-Bench Verified: 93.9%, CharXiv-R: 93.2%. GLM-5.3 scores Terminal-Bench 2.1: 88.2%, CyberGym: 84.5%, FrontierSWE: 78.1%, Toolathlon: 73.0%, DeepSWE 1.1: 66.9%.

Is Claude Mythos Preview cheaper than GLM-5.3?

GLM-5.3 is 17.9x cheaper for input tokens. Claude Mythos Preview costs $25.00/M input and $125.00/M output via anthropic. GLM-5.3 costs $1.40/M input and $4.40/M output via z.

What are the context window sizes for Claude Mythos Preview and GLM-5.3?

Claude Mythos Preview supports an unknown number of tokens and GLM-5.3 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Mythos Preview and GLM-5.3?

Key differences include input pricing ($25.00 vs $1.40/M), multimodal support (yes vs no), licensing (Proprietary vs Unknown). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos Preview and GLM-5.3?

Claude Mythos Preview is developed by Anthropic and GLM-5.3 is developed by Zhipu AI.

Related comparisons