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Claude Opus 4.8 vs GLM-5.3-Flash

Claude Opus 4.8 has a slight edge in benchmark performance. GLM-5.3-Flash is 42.1x cheaper per token.

Anthropic · Zhipu AI · Updated for 2026

Which is better?

Claude Opus 4.8 outperforms in 3 benchmarks (CharXiv-R, Humanity's Last Exam, OfficeQA Pro), while GLM-5.3-Flash is better at 2 benchmarks (DeepSWE 1.1, Toolathlon). Claude Opus 4.8 has a slight edge in benchmark performance.

On price, GLM-5.3-Flash is roughly 42.1x 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 Opus 4.8

  • you want the strongest raw capability — it leads on 3 of 5 shared benchmarks

Choose GLM-5.3-Flash

  • cost matters — it's about 42.1x cheaper per token
  • 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.

Claude Opus 4.8
Anthropic
GLM-5.3-Flash
Zhipu AI
Benchmark wins
3 of 5
2 of 5
Input price
$5.00 / M
$0.15 / M
Output price
$25.00 / M
$0.50 / M
Context window
1,000,000
1,000,000
Released
May 2026
Aug 2026
License
Proprietary
MIT

Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

Claude Opus 4.8 outperforms in 3 benchmarks (CharXiv-R, Humanity's Last Exam, OfficeQA Pro), while GLM-5.3-Flash is better at 2 benchmarks (DeepSWE 1.1, Toolathlon).

Claude Opus 4.8 has a slight edge in benchmark performance.

Wed Aug 26 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Pricing Analysis

Price comparison per million tokens

GLM-5.3-Flash costs less

For input processing, Claude Opus 4.8 ($5.00/1M tokens) is 33.3x more expensive than GLM-5.3-Flash ($0.15/1M tokens).

For output processing, Claude Opus 4.8 ($25.00/1M tokens) is 50.0x more expensive than GLM-5.3-Flash ($0.50/1M tokens).

In conclusion, Claude Opus 4.8 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 Aug 26 2026 • llm-stats.com
Anthropic
Claude Opus 4.8
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
Zhipu AI
GLM-5.3-Flash
Input tokens$0.15
Output tokens$0.50
Best providerUnknown Organization
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Both models have the same input context window of 1,000,000 tokens. GLM-5.3-Flash can generate longer responses up to 131,072 tokens, while Claude Opus 4.8 is limited to 128,000 tokens.

Anthropic
Claude Opus 4.8
Input1,000,000 tokens
Output128,000 tokens
Zhipu AI
GLM-5.3-Flash
Input1,000,000 tokens
Output131,072 tokens
Wed Aug 26 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.8 and GLM-5.3-Flash support multimodal inputs.

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

Claude Opus 4.8

Text
Images
Audio
Video

GLM-5.3-Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 4.8 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 4.8

Proprietary

Closed source

GLM-5.3-Flash

MIT

Open weights

Release Timeline

When each model was launched

Claude Opus 4.8 was released on 2026-05-28, while GLM-5.3-Flash was released on 2026-08-26.

GLM-5.3-Flash is 3 months newer than Claude Opus 4.8.

Claude Opus 4.8

May 28, 2026

3 months ago

GLM-5.3-Flash

Aug 26, 2026

0 days ago

3mo newer

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-5.3-Flash is available from 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-5.3-Flash

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?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Opus 4.8 and GLM-5.3-Flash side-by-side, then vote on the output you prefer.

Claude Opus 4.8
✓ Preferred
GLM-5.3-Flash
Open in Playground

FAQ

Common questions about Claude Opus 4.8 vs GLM-5.3-Flash.

Which is better, Claude Opus 4.8 or GLM-5.3-Flash?

Claude Opus 4.8 has a slight edge in benchmark performance. Claude Opus 4.8 is made by Anthropic and GLM-5.3-Flash 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-5.3-Flash 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-5.3-Flash scores CharXiv-R: 89.4%, Terminal-Bench 2.1: 84.3%, MMVU: 80.5%, Toolathlon: 78.4%, MVBench: 77.8%.

Is Claude Opus 4.8 cheaper than GLM-5.3-Flash?

GLM-5.3-Flash is 33.3x cheaper for input tokens. Claude Opus 4.8 costs $5.00/M input and $25.00/M output via anthropic. GLM-5.3-Flash costs $0.15/M input and $0.50/M output via z.

What are the context window sizes for Claude Opus 4.8 and GLM-5.3-Flash?

Claude Opus 4.8 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 4.8 and GLM-5.3-Flash?

Key differences include input pricing ($5.00 vs $0.15/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.8 and GLM-5.3-Flash?

Claude Opus 4.8 is developed by Anthropic and GLM-5.3-Flash is developed by Zhipu AI.

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