GPT-5.2 Pro vs Mercury 3
GPT-5.2 Pro leads the LLM Stats Score 43.0 to 36.1. Mercury 3 is 355.4x cheaper per token.
OpenAI · Inception · Updated for 2026
Which is better?
GPT-5.2 Pro leads the overall LLM Stats Score 43.0 to 36.1, ranking #58 overall.
In the 1 individual benchmarks reported for both models, GPT-5.2 Pro wins 1; this is a narrower head-to-head signal than the composite indexes.
On price, Mercury 3 is roughly 355.4x 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 GPT-5.2 Pro
- overall performance matters — it scores 43.0 and ranks #58 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
Choose Mercury 3
- cost matters — it's about 355.4x 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
At a glance
The differences that matter most.
Individual benchmarks
7 reported for GPT-5.2 Pro · 12 for Mercury 3
GPT-5.2 Pro outperforms in 1 benchmarks (GPQA), while Mercury 3 is better at 0 benchmarks.
GPT-5.2 Pro 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, GPT-5.2 Pro ($21.00/1M tokens) is 210.0x more expensive than Mercury 3 ($0.10/1M tokens).
For output processing, GPT-5.2 Pro ($168.00/1M tokens) is 480.0x more expensive than Mercury 3 ($0.35/1M tokens).
In conclusion, GPT-5.2 Pro 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 GPT-5.2 Pro's 400,000 tokens. Mercury 3 can generate longer responses up to 131,072 tokens, while GPT-5.2 Pro is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
GPT-5.2 Pro supports multimodal inputs, whereas Mercury 3 does not.
GPT-5.2 Pro can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5.2 Pro
Mercury 3
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
GPT-5.2 Pro was released on 2025-12-11, while Mercury 3 was released on 2026-10-19.
Mercury 3 is 10 months newer than GPT-5.2 Pro.
Dec 11, 2025
10 months ago
Oct 19, 2026
3 days ago
10mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
GPT-5.2 Pro is available from OpenAI. Mercury 3 is available from Inception.
GPT-5.2 Pro
Mercury 3
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.2 Pro and Mercury 3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.2 Pro vs Mercury 3.