Mercury 3 vs Solar Pro 4
Mercury 3 and Solar Pro 4 are closely matched at 36.1 and 34.7 on the LLM Stats Score. Mercury 3 is 3.2x cheaper per token.
Inception · Upstage · Updated for 2026
Which is better?
Mercury 3 and Solar Pro 4 are closely matched on the overall LLM Stats Score at 36.1 and 34.7.
In the 3 individual benchmarks reported for both models, Mercury 3 wins 3; this is a narrower head-to-head signal than the composite indexes.
On price, Mercury 3 is roughly 3.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Mercury 3 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Mercury 3
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
- cost matters — it's about 3.2x cheaper per token
- you process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Oct 2026
Choose Solar Pro 4
- you want predictable pricing at $0.30/M input and $1.20/M output
At a glance
The differences that matter most.
Individual benchmarks
12 reported for Mercury 3 · 9 for Solar Pro 4
Mercury 3 outperforms in 3 benchmarks (AA-LCR, GPQA, Tau3 Banking), while Solar Pro 4 is better at 0 benchmarks.
Mercury 3 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Mercury 3 ($0.10/1M tokens) is 3.0x cheaper than Solar Pro 4 ($0.30/1M tokens).
For output processing, Mercury 3 ($0.35/1M tokens) is 3.4x cheaper than Solar Pro 4 ($1.20/1M tokens).
In conclusion, Solar Pro 4 is more expensive than Mercury 3.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Mercury 3 accepts 1,000,000 input tokens compared to Solar Pro 4's 524,288 tokens. Both models can generate responses up to 131,072 tokens.
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Mercury 3 was released on 2026-10-19, while Solar Pro 4 was released on 2026-08-06.
Mercury 3 is 2 months newer than Solar Pro 4.
Oct 19, 2026
0 days ago
2mo newerAug 6, 2026
2 months ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Mercury 3 is available from Inception. Solar Pro 4 is available from Upstage.
Mercury 3
Solar Pro 4
Outputs Comparison
Judge for yourself.
Run your own prompts against Mercury 3 and Solar Pro 4 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Mercury 3 vs Solar Pro 4.