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Claude Opus 5.5 vs GLM-5.3-Flash

Claude Opus 5.5 leads the LLM Stats Score 60.5 to 49.0. GLM-5.3-Flash is 33.7x cheaper per token.

Anthropic · Zhipu AI · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 60.5 to 49.0, ranking #1 overall.

In the 4 individual benchmarks reported for both models, Claude Opus 5.5 wins 3; this is a narrower head-to-head signal than the composite indexes.

On price, GLM-5.3-Flash is roughly 33.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GLM-5.3-Flash also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Opus 5.5

  • overall performance matters — it scores 60.5 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 3 of 4 exact shared results
  • you want the most recent training data — it shipped Sep 2026

Choose GLM-5.3-Flash

  • cost matters — it's about 33.7x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Opus 5.5
Anthropic
GLM-5.3-Flash
Zhipu AI
Core performance indexes
LLM Stats Score
60.5
#1
49.0
#23
Reasoning
59.1
#1
48.0
#22
Coding
51.3
#1
33.0
#43
Agents
45.5
#1
35.5
#21
Cost, coverage & limits
Benchmark wins
3 of 4
1 of 4
Input price
$4.00 / M
$0.15 / M
Output price
$20.00 / M
$0.50 / M
Context window
1,000,000
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

3 shared
Index
Claude Opus 5.5
GLM-5.3-Flash
Vision
41.2#1
30.9#31
Tool use
32.4#3
28.5#17
Multimodal
40.7#1
30.6#32
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 15 for GLM-5.3-Flash

4 shared

Claude Opus 5.5 outperforms in 3 benchmarks (Chartography, DeepSWE 1.1, OfficeQA Pro), while GLM-5.3-Flash is better at 1 benchmark (AutomationBench).

Claude Opus 5.5 shows notably better performance in the majority of benchmarks.

Wed Oct 07 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GLM-5.3-Flash costs less

For input processing, Claude Opus 5.5 ($4.00/1M tokens) is 26.7x more expensive than GLM-5.3-Flash ($0.15/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 40.0x more expensive than GLM-5.3-Flash ($0.50/1M tokens).

In conclusion, Claude Opus 5.5 is more expensive than GLM-5.3-Flash.*

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

Lowest available price from all providers
Wed Oct 07 2026 • llm-stats.com
Anthropic
Claude Opus 5.5
Input tokens$4.00
Output tokens$20.00
Best providerAnthropic
Zhipu AI
GLM-5.3-Flash
Input tokens$0.15
Output tokens$0.50
Best providerDeepinfra
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

GLM-5.3-Flash accepts 1,048,576 input tokens compared to Claude Opus 5.5's 1,000,000 tokens. GLM-5.3-Flash can generate longer responses up to 1,048,576 tokens, while Claude Opus 5.5 is limited to 128,000 tokens.

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
Zhipu AI
GLM-5.3-Flash
Input1,048,576 tokens
Output1,048,576 tokens
Wed Oct 07 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5.5 and GLM-5.3-Flash support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 5.5

Text
Images
Audio
Video

GLM-5.3-Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 5.5 is licensed under a proprietary license, while GLM-5.3-Flash uses MIT.

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

Claude Opus 5.5

Proprietary

Closed source

GLM-5.3-Flash

MIT

Open weights

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while GLM-5.3-Flash was released on 2026-08-26.

Claude Opus 5.5 is 1 month newer than GLM-5.3-Flash.

Claude Opus 5.5

Sep 22, 2026

2 weeks ago

3w newer
GLM-5.3-Flash

Aug 26, 2026

1 months ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a documented knowledge cutoff of 2026-06-01, while GLM-5.3-Flash's cutoff date is not specified.

We can confirm Claude Opus 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without GLM-5.3-Flash's cutoff date.

Claude Opus 5.5

Jun 2026

GLM-5.3-Flash

—

Provider Availability

Claude Opus 5.5 is available from Anthropic. GLM-5.3-Flash is available from DeepInfra, FriendliAI, Novita, ZAI.

Claude Opus 5.5

anthropic logo
Anthropic
Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

GLM-5.3-Flash

deepinfra logo
Deepinfra
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
friendli logo
FriendliAI
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
novita logo
Novita
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
z logo
Unknown Organization
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and GLM-5.3-Flash side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
GLM-5.3-Flash
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs GLM-5.3-Flash.

Which is better, Claude Opus 5.5 or GLM-5.3-Flash?

Claude Opus 5.5 leads the LLM Stats Score 60.5 to 49.0. Claude Opus 5.5 is made by Anthropic and GLM-5.3-Flash is made by Zhipu AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 5.5 compare to GLM-5.3-Flash in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. GLM-5.3-Flash scores CharXiv-R: 89.4%, Terminal-Bench 2.1: 84.3%, MMVU: 80.5%, Toolathlon: 78.4%, Chartography: 78.0%.

Is Claude Opus 5.5 cheaper than GLM-5.3-Flash?

GLM-5.3-Flash is 26.7x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. GLM-5.3-Flash costs $0.15/M input and $0.50/M output via deepinfra.

What are the context window sizes for Claude Opus 5.5 and GLM-5.3-Flash?

Claude Opus 5.5 supports 1.0M tokens and GLM-5.3-Flash 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 Opus 5.5 and GLM-5.3-Flash?

Key differences include LLM Stats Score (60.5 vs 49.0), context window (1.0M vs 1.0M), input pricing ($4.00 vs $0.15/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and GLM-5.3-Flash?

Claude Opus 5.5 is developed by Anthropic and GLM-5.3-Flash is developed by Zhipu AI.

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