The AI arena is free today

Open Superagent

Mercury 3 vs o3

Mercury 3 leads the LLM Stats Score 36.1 to 30.6. Mercury 3 is 21.5x cheaper per token.

Inception · OpenAI · Updated for 2026

Which is better?

Mercury 3 leads the overall LLM Stats Score 36.1 to 30.6, ranking #98 overall.

The models split the 2 individual benchmarks reported for both models evenly.

On price, Mercury 3 is roughly 21.5x 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

  • overall performance matters — it scores 36.1 and ranks #98 on LLM Stats
  • your work emphasizes reasoning and agents — it leads those capability indexes
  • cost matters — it's about 21.5x 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 o3

  • you want predictable pricing at $2.00/M input and $8.00/M output

At a glance

The differences that matter most.

Core performance indexes
36.1
#98
30.6
#137
34.8
#103
30.4
#138
21.5
#105
14.6
#152
19.4
#84
3.6
#183
Cost, coverage & limits
Benchmark wins
1 of 2
1 of 2
Input price
$0.10 / M
$2.00 / M
Output price
$0.35 / M
$8.00 / M
Context window
1,000,000
200,000

Individual benchmarks

12 reported for Mercury 3 · 22 for o3

2 shared

Mercury 3 outperforms in 1 benchmarks (GPQA), while o3 is better at 1 benchmark (Multi-Challenge).

Both models are evenly matched across the benchmarks.

Thu Oct 22 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Mercury 3 costs less

For input processing, Mercury 3 ($0.10/1M tokens) is 20.0x cheaper than o3 ($2.00/1M tokens).

For output processing, Mercury 3 ($0.35/1M tokens) is 22.9x cheaper than o3 ($8.00/1M tokens).

In conclusion, o3 is more expensive than Mercury 3.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Thu Oct 22 2026 • llm-stats.com
Inception
Mercury 3
Input tokens$0.10
Output tokens$0.35
Best providerInception
OpenAI
o3
Input tokens$2.00
Output tokens$8.00
Best providerOpenAI
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Mercury 3 accepts 1,000,000 input tokens compared to o3's 200,000 tokens. Mercury 3 can generate longer responses up to 131,072 tokens, while o3 is limited to 100,000 tokens.

Inception
Mercury 3
Input1,000,000 tokens
Output131,072 tokens
OpenAI
o3
Input200,000 tokens
Output100,000 tokens
Thu Oct 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

o3 supports multimodal inputs, whereas Mercury 3 does not.

o3 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Mercury 3

Text
Images
Audio
Video

o3

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Mercury 3

Proprietary

Closed source

o3

Proprietary

Closed source

Release Timeline

When each model was launched

Mercury 3 was released on 2026-10-19, while o3 was released on 2025-04-16.

Mercury 3 is 18 months newer than o3.

Mercury 3

Oct 19, 2026

0 days ago

1.5yr newer
o3

Apr 16, 2025

1.5 years ago

Knowledge Cutoff

When training data ends

o3 has a documented knowledge cutoff of 2024-05-31, while Mercury 3's cutoff date is not specified.

We can confirm o3's training data extends to 2024-05-31, but cannot make a direct comparison without Mercury 3's cutoff date.

Mercury 3

—

o3

May 2024

Provider Availability

Mercury 3 is available from Inception. o3 is available from OpenAI.

Mercury 3

inception logo
Inception
Input Price:Input: $0.10/1MOutput Price:Output: $0.35/1M

o3

openai logo
OpenAI
Input Price:Input: $2.00/1MOutput Price:Output: $8.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Mercury 3 and o3 side-by-side, then vote on the output you prefer.

Mercury 3
✓ Preferred
o3
Open in Playground

FAQ

Common questions about Mercury 3 vs o3.

Which is better, Mercury 3 or o3?

Mercury 3 leads the LLM Stats Score 36.1 to 30.6. Mercury 3 is made by Inception and o3 is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Mercury 3 compare to o3 in benchmarks?

Mercury 3 scores GPQA: 89.2%, AA-LCR: 77.7%, IFBench: 76.8%, MRCR v2: 75.5%, DeepSearchQA: 71.3%. o3 scores COLLIE: 98.4%, AIME 2024: 91.6%, ARC-AGI: 88.0%, MathVista: 86.8%, AIME 2025: 86.4%.

Is Mercury 3 cheaper than o3?

Mercury 3 is 20.0x cheaper for input tokens. Mercury 3 costs $0.10/M input and $0.35/M output via inception. o3 costs $2.00/M input and $8.00/M output via openai.

What are the context window sizes for Mercury 3 and o3?

Mercury 3 supports 1.0M tokens and o3 supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Mercury 3 and o3?

Key differences include LLM Stats Score (36.1 vs 30.6), context window (1.0M vs 200K), input pricing ($0.10 vs $2.00/M), multimodal support (no vs yes). See the full comparison above for benchmark-by-benchmark results.

Who makes Mercury 3 and o3?

Mercury 3 is developed by Inception and o3 is developed by OpenAI.