Claude Opus 4.8 vs GLM 5.1
API pricing, context window and capabilities for Claude Opus 4.8 and GLM 5.1, side by side. Prices are the cheapest serving route per 1M tokens, verified against LiteLLM and OpenRouter.
Verdict
computed from the published numbersClaude Opus 4.8 wins on coding, on intelligence and on context window. GLM 5.1 wins on price.
Price
GLM 5.1
Coding
Claude Opus 4.8
Intelligence
Claude Opus 4.8
Context window
Claude Opus 4.8
Key takeaways
who wins on what, from the published numbersClaude Opus 4.8 wins
- Larger context window (1M vs 203K)
- More serving providers (4 vs 2)
- Supports vision
- Supports structured output
GLM 5.1 wins
- Cheaper input ($5.00 vs $1.05 /1M)
- Cheaper output ($25.00 vs $3.50 /1M)
Cheaper overall
GLM 5.1
$1.05 + $3.50 /1M
Larger context
Claude Opus 4.8
1M
More providers
Claude Opus 4.8
4 providers
Pricing & specs
cheapest serving route · per 1M tokens| Claude Opus 4.8 | GLM 5.1 | |
|---|---|---|
| Input $/1M | $5.00 | $1.05 best |
| Output $/1M | $25.00 | $3.50 best |
| Context window | 1M best | 203K |
| Max output | 128K | 128K |
| Serving providers | 4 best | 2 |
| Released | 2026-05-28 | 2026-04-07 |
Benchmarks
Artificial Analysis indices, side by side| Claude Opus 4.8 | GLM 5.1 | |
|---|---|---|
| Intelligence | 55.7 best | 40.2 |
| Coding | 74.3 best | 55.8 |
| GPQA Diamond | 92% best | 87% |
| Output speed | 68 t/s | 91 t/s best |
| Latency (TTFT) | 38.57s | 10.49s best |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
Claude Opus 4.8
via Amazon Bedrock
$50
GLM 5.1
via OpenRouter
$8.75
Capabilities
feature support, side by side| Feature | Claude Opus 4.8 | GLM 5.1 |
|---|---|---|
| Vision | ✓ | — |
| Tool use | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
| Audio | — | — |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | — |
| Web search | — | — |
Related comparisons
Frequently asked questions
Which is cheaper, Claude Opus 4.8 or GLM 5.1?
GLM 5.1 is cheaper for input ($5.00 vs $1.05 per 1M tokens). GLM 5.1 is cheaper for output ($25.00 vs $3.50 per 1M tokens).
What is the context window difference between Claude Opus 4.8 and GLM 5.1?
Claude Opus 4.8 has a 1M-token context window and GLM 5.1 has 203K tokens, so Claude Opus 4.8 can take a larger prompt.
How do Claude Opus 4.8 and GLM 5.1 compare on benchmarks?
On the tracked Artificial Analysis indices, Claude Opus 4.8 leads on coding, and Claude Opus 4.8 leads on intelligence.
Pricing verified against LiteLLM + OpenRouter + provider pages · refreshed daily
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