| Signal | Grok 4 Fast | Delta | Mercury |
|---|---|---|---|
Capabilities | 100 | +50 | |
Benchmarks | 70 | +15 | |
Pricing | 1 | 0 | |
Context window size | 100 | +19 | |
Recency | 99 | +15 | |
Output Capacity | 75 | 0 | |
| Overall Result | 4 wins | of 6 | 2 wins |
30
days ranked higher
0
days
0
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xAI
Inception
Grok 4 Fast saves you $17.50/month
That's $210.00/year compared to Mercury at your current usage level of 100K calls/month.
| Metric | Grok 4 Fast | Mercury | Winner |
|---|---|---|---|
| Overall Score | 83 | 63 | Grok 4 Fast |
| Rank | #52 | #201 | Grok 4 Fast |
| Quality Rank | #52 | #201 | Grok 4 Fast |
| Adoption Rank | #52 | #201 | Grok 4 Fast |
| Parameters | -- | -- | -- |
| Context Window | 2000K | 128K | Grok 4 Fast |
| Pricing | $0.20/$0.50/M | $0.25/$0.75/M | -- |
| Signal Scores | |||
| Capabilities | 100 | 50 | Grok 4 Fast |
| Benchmarks | 70 | 55 | Grok 4 Fast |
| Pricing | 1 | 1 | Mercury |
| Context window size | 100 | 81 | Grok 4 Fast |
| Recency | 99 | 84 | Grok 4 Fast |
| Output Capacity | 75 | 75 | Mercury |
Our composite score (0–100) combines six weighted signals: benchmark performance (25%), pricing efficiency (25%), context window size (15%), model recency (15%), output capacity (10%), and capability versatility (10%). Here's what the scores mean for these two models:
Scores 83/100 (rank #52), placing it in the top 82% of all 290 models tracked.
Scores 63/100 (rank #201), placing it in the top 31% of all 290 models tracked.
Grok 4 Fast has a 20-point advantage, which typically translates to noticeably stronger performance on complex reasoning, code generation, and multi-step tasks.
Grok 4 Fast offers 30% better value per quality point. At 1M tokens/day, you'd spend $10.50/month with Grok 4 Fast vs $15.00/month with Mercury - a $4.50 monthly difference.
Both models have comparable response speeds. For most applications, the latency difference is negligible.
When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.
Code generation & review
Higher benchmark score (0/100) indicates stronger performance on coding tasks like generating functions, debugging, and refactoring
Customer support chatbot
Faster response time (speed score 0/100) is critical for user-facing chat. Grok 4 Fast also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (2000K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($0.50/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (83/100) correlates with better nuance, coherence, and style in long-form content
Image understanding & OCR
Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly
Grok 4 Fast clearly outperforms Mercury with a significant 20.000000000000007-point lead. For most general use cases, Grok 4 Fast is the stronger choice. However, Mercury may still excel in niche scenarios.
Best for Quality
Grok 4 Fast
Marginally better benchmark scores; both are excellent
Best for Cost
Grok 4 Fast
30% lower pricing; better value at scale
Best for Reliability
Grok 4 Fast
Higher uptime and faster response speeds
Best for Prototyping
Grok 4 Fast
Stronger community support and better developer experience
Best for Production
Grok 4 Fast
Wider enterprise adoption and proven at scale
by xAI
| Capability | Grok 4 Fast | Mercury |
|---|---|---|
| Vision (Image Input)differs | ||
| Function Calling | ||
| Streaming | ||
| JSON Mode | ||
| Reasoningdiffers | ||
| Web Searchdiffers | ||
| Image Output |
xAI
Inception
Grok 4 Fast saves you $0.3900/month
That's 29% cheaper than Mercury at 1,000 tokens/request and 100 requests/day.
Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.
| Parameter | Grok 4 Fast | Mercury |
|---|---|---|
| Context Window | 2M | 128K |
| Max Output Tokens | 30,000 | 32,000 |
| Open Source | No | No |
| Created | Sep 19, 2025 | Jun 26, 2025 |
Grok 4 Fast scores 83/100 (rank #52) compared to Mercury's 63/100 (rank #201), giving it a 20-point advantage. Grok 4 Fast is the stronger overall choice, though Mercury may excel in specific areas like certain benchmarks.
Grok 4 Fast is ranked #52 and Mercury is ranked #201 out of 290+ AI models. Rankings use a composite score combining benchmark performance (25%), pricing (25%), context window (15%), recency (15%), output capacity (10%), and versatility (10%). Scores update hourly.
Grok 4 Fast is cheaper at $0.50/M output tokens vs Mercury's $0.75/M output tokens - 1.5x more expensive. Input token pricing: Grok 4 Fast at $0.20/M vs Mercury at $0.25/M.
Grok 4 Fast has a larger context window of 2,000,000 tokens compared to Mercury's 128,000 tokens. A larger context window means the model can process longer documents and conversations.