Grok 3 vs Molmo 72B
Compare Grok 3 and Molmo 72B: pricing, performance, context window, latency, and best use cases. Side-by-side comparison on XALEN.
Updated 2026-05-21 · By Abhishek Raj · Our methodology
| Feature | Grok 3 | Molmo 72B |
|---|---|---|
| Category | Frontier | Vision |
| Parameters | ~800B | 72B |
| Context Window | 128K | 128K |
| Input Price | $0.10/1M tokens | $0.04/1M tokens |
| Output Price | $0.25/1M tokens | $0.08/1M tokens |
| Latency | ~500ms | ~350ms |
Choose Grok 3 when:
- ✓ Transit predictions
- ✓ Creative interpretations
- ✓ Research
Strong reasoning, Real-time knowledge, Creative output
Choose Molmo 72B when:
- ✓ Visual grounding
- ✓ Object detection
- ✓ Research
Fully open, Good pointing/grounding, Transparent
Verdict: Grok 3 vs Molmo 72B
For cost efficiency, Molmo 72B wins at $0.04/1M input tokens. For speed, Molmo 72B is faster at ~350ms. Grok 3 excels at Transit predictions while Molmo 72B is better for Visual grounding. Both are available on XALEN through a single API — try them in the Playground to see which fits your workload.
Detailed Analysis
Pricing Comparison
Grok 3 costs $0.10/1M input tokens and $0.25/1M output tokens. Molmo 72B costs $0.04 input and $0.08 output. Molmo 72B is 2.5x cheaper on input tokens. XALEN offers batch processing at 50% discount on both models.
Performance & Context
Grok 3 has a 128K context window with ~500ms latency. Molmo 72B offers 128K context at ~350ms. Both have identical context windows.
Best For
Grok 3 (Frontier) is optimized for: Transit predictions, Creative interpretations, Research. Molmo 72B (Vision) works best for: Visual grounding, Object detection, Research.
Try Both on XALEN
Both models are available through XALEN's OpenAI-compatible API. Switch between them by changing the model parameter:
from xalen import XALEN
client = XALEN(api_key="xln_test_YOUR_KEY")
# Use Grok 3
response_a = client.chat.completions.create(
model="grok-3",
messages=[{"role": "user", "content": "Your question here"}]
)
# Use Molmo 72B
response_b = client.chat.completions.create(
model="molmo-72b",
messages=[{"role": "user", "content": "Your question here"}]
)Frequently Asked Questions
Which is better, Grok 3 or Molmo 72B?
Grok 3 (Frontier, ~800B) offers Strong reasoning. Molmo 72B (Vision, 72B) offers Fully open. Choose Grok 3 for Transit predictions or Molmo 72B for Visual grounding.
How much does Grok 3 cost vs Molmo 72B?
Grok 3: $0.10/1M input, $0.25/1M output. Molmo 72B: $0.04/1M input, $0.08/1M output. Both available on XALEN with batch processing at 50% discount.
Can I use both models on XALEN?
Yes. XALEN provides 200+ models through a single OpenAI-compatible API. Switch between Grok 3 and Molmo 72B by changing the model parameter. No code changes needed.
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Last updated: 2026-05-21. Pricing and specifications may change. Check pricing page for latest rates.