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Laguna S 2.1 vs Mercury 3

Laguna S 2.1 and Mercury 3 are closely matched at 39.7 and 36.1 on the LLM Stats Score. Laguna S 2.1 is 1.3x cheaper per token.

Poolside · Inception · Updated for 2026

Which is better?

Laguna S 2.1 and Mercury 3 are closely matched on the overall LLM Stats Score at 39.7 and 36.1.

On price, Laguna S 2.1 is roughly 1.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Laguna S 2.1 also accepts a larger context window (1,048,576 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 Laguna S 2.1

  • cost matters — it's about 1.3x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window
  • you need open weights you can self-host or fine-tune

Choose Mercury 3

  • you want the most recent training data — it shipped Oct 2026

At a glance

The differences that matter most.

Laguna S 2.1
Poolside
Mercury 3
Inception
Core performance indexes
LLM Stats Score
39.7
#73
36.1
#98
Reasoning
39.7
#71
34.8
#103
Coding
29.1
#69
21.5
#105
Agents
23.3
#75
19.4
#84
Cost, coverage & limits
Benchmark wins
—
—
Input price
$0.10 / M
$0.10 / M
Output price
$0.20 / M
$0.35 / M
Context window
1,048,576
1,000,000

Individual benchmarks

6 reported for Laguna S 2.1 · 12 for Mercury 3

No common benchmarks found

Laguna S 2.1 and Mercury 3don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Laguna S 2.1 costs less

For input processing, Laguna S 2.1 ($0.10/1M tokens) costs the same as Mercury 3 ($0.10/1M tokens).

For output processing, Laguna S 2.1 ($0.20/1M tokens) is 1.7x cheaper than Mercury 3 ($0.35/1M tokens).

In conclusion, Mercury 3 is more expensive than Laguna S 2.1.*

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

Lowest available price from all providers
Thu Oct 22 2026 • llm-stats.com
Poolside
Laguna S 2.1
Input tokens$0.10
Output tokens$0.20
Best providerPoolside
Inception
Mercury 3
Input tokens$0.10
Output tokens$0.35
Best providerInception
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Laguna S 2.1 accepts 1,048,576 input tokens compared to Mercury 3's 1,000,000 tokens. Only Mercury 3 specifies output context (131,072 tokens).

Poolside
Laguna S 2.1
Input1,048,576 tokens
Output- tokens
Inception
Mercury 3
Input1,000,000 tokens
Output131,072 tokens
Thu Oct 22 2026 • llm-stats.com

License

Usage and distribution terms

Laguna S 2.1 is licensed under OpenMDW License v1.1, while Mercury 3 uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

Laguna S 2.1

OpenMDW License v1.1

Open weights

Mercury 3

Proprietary

Closed source

Release Timeline

When each model was launched

Laguna S 2.1 was released on 2026-07-21, while Mercury 3 was released on 2026-10-19.

Mercury 3 is 3 months newer than Laguna S 2.1.

Laguna S 2.1

Jul 21, 2026

3 months ago

Mercury 3

Oct 19, 2026

0 days ago

3mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Laguna S 2.1 is available from Poolside. Mercury 3 is available from Inception.

Laguna S 2.1

poolside logo
Poolside
Input Price:Input: $0.10/1MOutput Price:Output: $0.20/1M

Mercury 3

inception logo
Inception
Input Price:Input: $0.10/1MOutput Price:Output: $0.35/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Laguna S 2.1 and Mercury 3 side-by-side, then vote on the output you prefer.

Laguna S 2.1
✓ Preferred
Mercury 3
Open in Playground

FAQ

Common questions about Laguna S 2.1 vs Mercury 3.

Which is better, Laguna S 2.1 or Mercury 3?

Laguna S 2.1 and Mercury 3 are closely matched on the LLM Stats Score at 39.7 and 36.1. Laguna S 2.1 is made by Poolside and Mercury 3 is made by Inception. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Laguna S 2.1 compare to Mercury 3 in benchmarks?

Laguna S 2.1 scores SWE-bench Multilingual: 78.5%, Terminal-Bench 2.1: 70.2%, SWE-Bench Pro: 59.4%, Toolathlon: 49.7%, SWE Atlas - Codebase QnA: 46.2%. Mercury 3 scores GPQA: 89.2%, AA-LCR: 77.7%, IFBench: 76.8%, MRCR v2: 75.5%, DeepSearchQA: 71.3%.

Is Laguna S 2.1 cheaper than Mercury 3?

Both models cost $0.10 per million input tokens.

What are the context window sizes for Laguna S 2.1 and Mercury 3?

Laguna S 2.1 supports 1.0M tokens and Mercury 3 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Laguna S 2.1 and Mercury 3?

Key differences include LLM Stats Score (39.7 vs 36.1), context window (1.0M vs 1.0M), licensing (OpenMDW License v1.1 vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Laguna S 2.1 and Mercury 3?

Laguna S 2.1 is developed by Poolside and Mercury 3 is developed by Inception.

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