Claude 3.5 Sonnet vs GLM-5.3-Flash
Comparing Claude 3.5 Sonnet and GLM-5.3-Flash across benchmarks, pricing, and capabilities.
Anthropic · Zhipu AI · Updated for 2026
Which is better?
Claude 3.5 Sonnet and GLM-5.3-Flash trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
On price, GLM-5.3-Flash is roughly 25.3x 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 (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current benchmark, pricing, and model metadata for 2026.
Choose Claude 3.5 Sonnet
- you want predictable pricing at $3.00/M input and $15.00/M output
Choose GLM-5.3-Flash
- cost matters — it's about 25.3x cheaper per token
- you process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Aug 2026
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
Claude 3.5 Sonnet and GLM-5.3-Flashdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude 3.5 Sonnet ($3.00/1M tokens) is 20.0x more expensive than GLM-5.3-Flash ($0.15/1M tokens).
For output processing, Claude 3.5 Sonnet ($15.00/1M tokens) is 30.0x more expensive than GLM-5.3-Flash ($0.50/1M tokens).
In conclusion, Claude 3.5 Sonnet is more expensive than GLM-5.3-Flash.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GLM-5.3-Flash accepts 1,000,000 input tokens compared to Claude 3.5 Sonnet's 200,000 tokens. Claude 3.5 Sonnet can generate longer responses up to 200,000 tokens, while GLM-5.3-Flash is limited to 131,072 tokens.
Input Capabilities
Supported data types and modalities
Both Claude 3.5 Sonnet and GLM-5.3-Flash support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude 3.5 Sonnet
GLM-5.3-Flash
License
Usage and distribution terms
Claude 3.5 Sonnet 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.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
Claude 3.5 Sonnet was released on 2024-10-22, while GLM-5.3-Flash was released on 2026-08-26.
GLM-5.3-Flash is 22 months newer than Claude 3.5 Sonnet.
Oct 22, 2024
1.8 years ago
Aug 26, 2026
0 days ago
1.8yr newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Claude 3.5 Sonnet is available from Anthropic, Bedrock, Google. GLM-5.3-Flash is available from ZAI.
Claude 3.5 Sonnet
GLM-5.3-Flash
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude 3.5 Sonnet and GLM-5.3-Flash side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude 3.5 Sonnet vs GLM-5.3-Flash.