Claude Sonnet 5 vs Mercury 2
API pricing, context window and capabilities for Claude Sonnet 5 and Mercury 2, side by side. Prices are the cheapest serving route per 1M tokens, verified against LiteLLM and OpenRouter.
Verdict
computed from the published numbersClaude Sonnet 5 wins on intelligence and on context window. Mercury 2 wins on price. Benchmark data is unavailable for one or both models.
Price
Mercury 2
Coding
Not called
Intelligence
Claude Sonnet 5
Context window
Claude Sonnet 5
Key takeaways
who wins on what, from the published numbersClaude Sonnet 5 wins
- Larger context window (1M vs 128K)
- Higher max output (128K vs 50K)
- More serving providers (4 vs 1)
- Supports vision
- Has reasoning mode
Mercury 2 wins
- Cheaper input ($2.00 vs $0.25 /1M)
- Cheaper output ($10.00 vs $0.75 /1M)
Cheaper overall
Mercury 2
$0.25 + $0.75 /1M
Larger context
Claude Sonnet 5
1M
More providers
Claude Sonnet 5
4 providers
Pricing & specs
cheapest serving route · per 1M tokens| Claude Sonnet 5 | Mercury 2 | |
|---|---|---|
| Input $/1M | $2.00 | $0.25 best |
| Output $/1M | $10.00 | $0.75 best |
| Context window | 1M best | 128K |
| Max output | 128K best | 50K |
| Serving providers | 4 best | 1 |
| Released | 2026-06-30 | 2026-02-24 |
Benchmarks
Artificial Analysis indices, side by side| Claude Sonnet 5 | Mercury 2 | |
|---|---|---|
| Intelligence | 53.4 best | 25.3 |
| Coding | 71.5 | Not available |
| GPQA Diamond | 91% best | 77% |
| Output speed | 67 t/s | 602 t/s best |
| Latency (TTFT) | 42.19s | 2.73s best |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
Claude Sonnet 5
via Amazon Bedrock
$20
Mercury 2
via Inception
$2.00
Capabilities
feature support, side by side| Feature | Claude Sonnet 5 | Mercury 2 |
|---|---|---|
| Vision | ✓ | — |
| Tool use | ✓ | ✓ |
| Reasoning | ✓ | — |
| Audio | — | — |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Web search | — | — |
Related comparisons
Frequently asked questions
Which is cheaper, Claude Sonnet 5 or Mercury 2?
Mercury 2 is cheaper for input ($2.00 vs $0.25 per 1M tokens). Mercury 2 is cheaper for output ($10.00 vs $0.75 per 1M tokens).
What is the context window difference between Claude Sonnet 5 and Mercury 2?
Claude Sonnet 5 has a 1M-token context window and Mercury 2 has 128K tokens, so Claude Sonnet 5 can take a larger prompt.
How do Claude Sonnet 5 and Mercury 2 compare on benchmarks?
On the tracked Artificial Analysis indices, Claude Sonnet 5 leads on intelligence.
Pricing verified against LiteLLM + OpenRouter + provider pages · refreshed daily
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