CtrlAltDebrief

Grok 4.3 vs Mercury 2

API pricing, context window and capabilities for Grok 4.3 and Mercury 2, side by side. Prices are the cheapest listed serving route per 1M tokens, from LiteLLM and OpenRouter.

Verdict

computed from the published numbers

Grok 4.3 wins on Terminal-Bench, on intelligence and on context window. Mercury 2 wins on price.

Price
Mercury 2
Terminal-Bench
Grok 4.3
Intelligence
Grok 4.3
Context window
Grok 4.3

Key takeaways

who wins on what, from the published numbers

Grok 4.3 wins

  • Larger context window (1M vs 128K)
  • Higher max output (1M vs 50K)
  • More serving providers (6 vs 3)
  • Supports vision
  • Has reasoning mode
  • Has web search

Mercury 2 wins

  • Cheaper input ($1.25 vs $0.25 /1M)
  • Cheaper output ($2.50 vs $0.75 /1M)
Cheaper overall
Mercury 2
$0.25 + $0.75 /1M
Larger context
Grok 4.3
1M
More providers
Grok 4.3
6 providers

Pricing & specs

cheapest listed route · per 1M tokens
On-demand listed rates, OpenRouter routed quotes and Vercel reseller quotes. Enterprise commitments can be materially lower.
Grok 4.3Mercury 2
Input $/1M$1.25via xAI $0.25via Inception best
Output $/1M$2.50via xAI $0.75via Inception best
Context window1M best128K
Max output1M best50K
Serving providers6 best3
DateReleased Apr 18, 2026 Released Feb 24, 2026

Benchmarks

Benchmark scores, side by side
Grok 4.3Mercury 2
Intelligence24.9 best13.8
Terminal-Bench40% best27%
GPQA Diamond90% best77%
Output speed113 t/s 554 t/s best
Latency (TTFT)27.23s 6.83s best

Cost calculator

choose a serving route for each side
Input tokens / month
Output tokens / month
Grok 4.3
via OpenRouter
$8.75
Mercury 2
via Inception
$2.00

Capabilities

feature support, side by side
FeatureGrok 4.3Mercury 2
Vision✓—
Tool use✓✓
Reasoning✓—
Audio——
Prompt caching✓✓
Structured output✓✓
Web search✓—

Related comparisons

Frequently asked questions

Which is cheaper, Grok 4.3 or Mercury 2?
Mercury 2 is cheaper for input ($1.25 vs $0.25 per 1M tokens) from Inception. Mercury 2 is cheaper for output ($2.50 vs $0.75 per 1M tokens) from Inception.
What is the context window difference between Grok 4.3 and Mercury 2?
Grok 4.3 has a 1M-token context window and Mercury 2 has 128K tokens, so Grok 4.3 can take a larger prompt.
How do Grok 4.3 and Mercury 2 compare on benchmarks?
On the tracked benchmarks, Grok 4.3 leads on Terminal-Bench, and Grok 4.3 leads on intelligence.
Listed prices from LiteLLM, OpenRouter and Vercel · last checked Oct 14, 2026

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