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Claude Sonnet 5.5 vs GLM-5.3-Flash

Claude Sonnet 5.5 leads the LLM Stats Score 58.5 to 49.0. GLM-5.3-Flash is 16.8x cheaper per token.

Anthropic · Zhipu AI · Updated for 2026

Which is better?

Claude Sonnet 5.5 leads the overall LLM Stats Score 58.5 to 49.0, ranking #2 overall.

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

On price, GLM-5.3-Flash is roughly 16.8x 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 Sonnet 5.5

  • overall performance matters — it scores 58.5 and ranks #2 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 16.8x 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 Sonnet 5.5
Anthropic
GLM-5.3-Flash
Zhipu AI
Core performance indexes
LLM Stats Score
58.5
#2
49.0
#23
Reasoning
57.1
#2
48.0
#22
Coding
48.9
#2
33.0
#43
Agents
42.7
#3
35.5
#21
Cost, coverage & limits
Benchmark wins
3 of 4
1 of 4
Input price
$2.00 / M
$0.15 / M
Output price
$10.00 / 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 Sonnet 5.5
GLM-5.3-Flash
Vision
41.1#2
30.9#31
Tool use
34.1#2
28.5#17
Multimodal
40.6#2
30.6#32
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

47 reported for Claude Sonnet 5.5 · 15 for GLM-5.3-Flash

4 shared

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

Claude Sonnet 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 Sonnet 5.5 ($2.00/1M tokens) is 13.3x more expensive than GLM-5.3-Flash ($0.15/1M tokens).

For output processing, Claude Sonnet 5.5 ($10.00/1M tokens) is 20.0x more expensive than GLM-5.3-Flash ($0.50/1M tokens).

In conclusion, Claude Sonnet 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 Sonnet 5.5
Input tokens$2.00
Output tokens$10.00
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 Sonnet 5.5's 1,000,000 tokens. GLM-5.3-Flash can generate longer responses up to 1,048,576 tokens, while Claude Sonnet 5.5 is limited to 128,000 tokens.

Anthropic
Claude Sonnet 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 Sonnet 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 Sonnet 5.5

Text
Images
Audio
Video

GLM-5.3-Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Sonnet 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 Sonnet 5.5

Proprietary

Closed source

GLM-5.3-Flash

MIT

Open weights

Release Timeline

When each model was launched

Claude Sonnet 5.5 was released on 2026-09-28, while GLM-5.3-Flash was released on 2026-08-26.

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

Claude Sonnet 5.5

Sep 28, 2026

1 weeks ago

1mo newer
GLM-5.3-Flash

Aug 26, 2026

1 months ago

Knowledge Cutoff

When training data ends

Claude Sonnet 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 Sonnet 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 Sonnet 5.5

Jun 2026

GLM-5.3-Flash

—

Provider Availability

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

Claude Sonnet 5.5

anthropic logo
Anthropic
Input Price:Input: $2.00/1MOutput Price:Output: $10.00/1M

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 Sonnet 5.5 and GLM-5.3-Flash side-by-side, then vote on the output you prefer.

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

FAQ

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

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

Claude Sonnet 5.5 leads the LLM Stats Score 58.5 to 49.0. Claude Sonnet 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 Sonnet 5.5 compare to GLM-5.3-Flash in benchmarks?

Claude Sonnet 5.5 scores BenchCAD (with Python tool): 96.3%, ArXivMath (with tools): 95.2%, Global-MMLU: 92.1%, MILU: 91.6%, SWE-bench Multilingual: 90.3%. 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 Sonnet 5.5 cheaper than GLM-5.3-Flash?

GLM-5.3-Flash is 13.3x cheaper for input tokens. Claude Sonnet 5.5 costs $2.00/M input and $10.00/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 Sonnet 5.5 and GLM-5.3-Flash?

Claude Sonnet 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 Sonnet 5.5 and GLM-5.3-Flash?

Key differences include LLM Stats Score (58.5 vs 49.0), context window (1.0M vs 1.0M), input pricing ($2.00 vs $0.15/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

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

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

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