Gemini 3.5 Flash vs GLM 5.1
API pricing, context window and capabilities for Gemini 3.5 Flash and GLM 5.1, side by side. Prices are the cheapest listed serving route per 1M tokens, from LiteLLM and OpenRouter.
Verdict
computed from the published numbersGemini 3.5 Flash wins on Terminal-Bench, on intelligence and on context window. GLM 5.1 wins on price.
Price
GLM 5.1
Terminal-Bench
Gemini 3.5 Flash
Intelligence
Gemini 3.5 Flash
Context window
Gemini 3.5 Flash
Key takeaways
who wins on what, from the published numbersGemini 3.5 Flash wins
- Larger context window (1M vs 205K)
- Supports vision
- Supports audio
- Has web search
GLM 5.1 wins
- Cheaper input ($1.50 vs $1.05 /1M)
- Cheaper output ($9.00 vs $3.50 /1M)
- Higher max output (66K vs 203K)
- More serving providers (7 vs 12)
Cheaper overall
GLM 5.1
$1.05 + $3.50 /1M
Larger context
Gemini 3.5 Flash
1M
More providers
GLM 5.1
12 providers
Pricing & specs
cheapest listed route · per 1M tokensOn-demand listed rates, OpenRouter routed quotes and Vercel reseller quotes. Enterprise commitments can be materially lower.
| Gemini 3.5 Flash | GLM 5.1 | |
|---|---|---|
| Input $/1M | $1.50via Google | $1.05via DeepInfra best |
| Output $/1M | $9.00via Google | $3.50via DeepInfra best |
| Context window | 1M best | 205K |
| Max output | 66K | 203K best |
| Serving providers | 7 | 12 best |
| Date | Released May 22, 2026 | Released Apr 7, 2026 |
Benchmarks
Benchmark scores, side by side| Gemini 3.5 Flash | GLM 5.1 | |
|---|---|---|
| Intelligence | 32.6 best | 26.1 |
| Terminal-Bench | 79% best | 62% |
| GPQA Diamond | 92% best | 87% |
| Output speed | 197 t/s best | 66 t/s |
| Latency (TTFT) | 17.14s | 1.71s best |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
Gemini 3.5 Flash
via OpenRouter
$17
GLM 5.1
via DeepInfra
$8.75
Capabilities
feature support, side by side| Feature | Gemini 3.5 Flash | GLM 5.1 |
|---|---|---|
| Vision | ✓ | — |
| Tool use | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
| Audio | ✓ | — |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Web search | ✓ | — |
Related comparisons
Frequently asked questions
Which is cheaper, Gemini 3.5 Flash or GLM 5.1?
GLM 5.1 is cheaper for input ($1.50 vs $1.05 per 1M tokens) from DeepInfra. GLM 5.1 is cheaper for output ($9.00 vs $3.50 per 1M tokens) from DeepInfra.
What is the context window difference between Gemini 3.5 Flash and GLM 5.1?
Gemini 3.5 Flash has a 1M-token context window and GLM 5.1 has 205K tokens, so Gemini 3.5 Flash can take a larger prompt.
How do Gemini 3.5 Flash and GLM 5.1 compare on benchmarks?
On the tracked benchmarks, Gemini 3.5 Flash leads on Terminal-Bench, and Gemini 3.5 Flash leads on intelligence.
Listed prices from LiteLLM, OpenRouter and Vercel · last checked Oct 14, 2026
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