Model Comparison

Claude Opus 4.8 vs GLM-5.1Which is better in 2026?

Claude Opus 4.8 significantly outperforms across most benchmarks. GLM-5.1 is 4.7x cheaper per token.

Verdict: Claude Opus 4.8 vs GLM-5.1 — which is better?

Claude Opus 4.8 (by Anthropic) and GLM-5.1 (by Zhipu AI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude Opus 4.8 outperforms in 12 benchmarks (BrowseComp, CyberGym, Finance Agent v2, FrontierSWE, GDPval-AA, GPQA, Humanity's Last Exam, LiveBench, MCP Atlas, SWE-Bench Pro, Terminal-Bench 2.0, Toolathlon), while GLM-5.1 is better at 0 benchmarks. Claude Opus 4.8 significantly outperforms across most benchmarks.

On price, GLM-5.1 is roughly 4.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 4.8 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude Opus 4.8 if…

  • you want the strongest raw capability — it leads on 12 of 12 shared benchmarks
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped May 2026

Choose GLM-5.1 if…

  • cost matters — it's about 4.7x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

12 benchmarks

Claude Opus 4.8 outperforms in 12 benchmarks (BrowseComp, CyberGym, Finance Agent v2, FrontierSWE, GDPval-AA, GPQA, Humanity's Last Exam, LiveBench, MCP Atlas, SWE-Bench Pro, Terminal-Bench 2.0, Toolathlon), while GLM-5.1 is better at 0 benchmarks.

Claude Opus 4.8 significantly outperforms across most benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GLM-5.1 costs less

For input processing, Claude Opus 4.8 ($5.00/1M tokens) is 3.6x more expensive than GLM-5.1 ($1.40/1M tokens).

For output processing, Claude Opus 4.8 ($25.00/1M tokens) is 5.7x more expensive than GLM-5.1 ($4.40/1M tokens).

In conclusion, Claude Opus 4.8 is more expensive than GLM-5.1.*

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

Lowest available price from all providers
Fri Jul 17 2026 • llm-stats.com
Anthropic
Claude Opus 4.8
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
Zhipu AI
GLM-5.1
Input tokens$1.40
Output tokens$4.40
Best providerFriendliAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Opus 4.8 accepts 1,000,000 input tokens compared to GLM-5.1's 200,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude Opus 4.8
Input1,000,000 tokens
Output128,000 tokens
Zhipu AI
GLM-5.1
Input200,000 tokens
Output128,000 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Opus 4.8 supports multimodal inputs, whereas GLM-5.1 does not.

Claude Opus 4.8 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 4.8

Text
Images
Audio
Video

GLM-5.1

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 4.8 is licensed under a proprietary license, while GLM-5.1 uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Opus 4.8

Proprietary

Closed source

GLM-5.1

MIT

Open weights

Release Timeline

When each model was launched

Claude Opus 4.8 was released on 2026-05-28, while GLM-5.1 was released on 2026-04-07.

Claude Opus 4.8 is 2 months newer than GLM-5.1.

Claude Opus 4.8

May 28, 2026

1 months ago

1mo newer
GLM-5.1

Apr 7, 2026

3 months 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 Opus 4.8 is available from Anthropic, Vertex AI. GLM-5.1 is available from FriendliAI, ZAI.

Claude Opus 4.8

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M
vertex logo
Unknown Organization
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

GLM-5.1

friendli logo
FriendliAI
Input Price:Input: $1.40/1MOutput Price:Output: $4.40/1M
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→

Key Takeaways

Anthropic
Larger context window (1,000,000 tokens)
Supports multimodal inputs
Higher BrowseComp score (84.3% vs 79.3%)
Higher CyberGym score (78.8% vs 68.7%)
Higher Finance Agent v2 score (53.9% vs 44.8%)
Higher FrontierSWE score (75.0% vs 31.0%)
Higher GDPval-AA score (54.6% vs 42.7%)
Higher GPQA score (93.6% vs 86.2%)
Higher Humanity's Last Exam score (57.9% vs 52.3%)
Higher LiveBench score (77.2% vs 70.2%)
Higher MCP Atlas score (82.2% vs 71.8%)
Higher SWE-Bench Pro score (69.2% vs 58.4%)
Higher Terminal-Bench 2.0 score (74.6% vs 69.0%)
Higher Toolathlon score (59.9% vs 40.7%)
Zhipu AI
Less expensive input tokens
Less expensive output tokens
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Opus 4.8 and GLM-5.1 side-by-side, then vote on the output you prefer.

Claude Opus 4.8
✓ Preferred
GLM-5.1
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.8
Zhipu AI
GLM-5.1

FAQ

Common questions about Claude Opus 4.8 vs GLM-5.1.

Which is better, Claude Opus 4.8 or GLM-5.1?

Claude Opus 4.8 significantly outperforms across most benchmarks. Claude Opus 4.8 is made by Anthropic and GLM-5.1 is made by Zhipu AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 4.8 compare to GLM-5.1 in benchmarks?

Claude Opus 4.8 scores GPQA: 93.6%, DeepSearchQA: 93.1%, CharXiv-R: 89.9%, SWE-Bench Verified: 88.6%, ScreenSpot Pro: 87.9%. GLM-5.1 scores Vending-Bench 2: 100.0%, AIME 2026: 95.3%, HMMT 2025: 94.0%, GPQA: 86.2%, IMO-AnswerBench: 83.8%.

Is Claude Opus 4.8 cheaper than GLM-5.1?

GLM-5.1 is 3.6x cheaper for input tokens. Claude Opus 4.8 costs $5.00/M input and $25.00/M output via anthropic. GLM-5.1 costs $1.40/M input and $4.40/M output via friendli.

What are the context window sizes for Claude Opus 4.8 and GLM-5.1?

Claude Opus 4.8 supports 1.0M tokens and GLM-5.1 supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 4.8 and GLM-5.1?

Key differences include context window (1.0M vs 200K), input pricing ($5.00 vs $1.40/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.8 and GLM-5.1?

Claude Opus 4.8 is developed by Anthropic and GLM-5.1 is developed by Zhipu AI.

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