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Comparison · 2 models · Updated Oct 4, 2026

Laguna XS 2.1 vs Mercury 2.5

Too close to call on our weighted score (Mercury 2.5 71, Laguna XS 2.1 68). The right pick depends on what you value most.

  1. Poolside

    Laguna XS 2.1

    Released Jul 2, 2026

    68/100
    • ECI—
    • Price$0.06 / $0.12
    • Context262K
  2. Inception

    Mercury 2.5

    Released Sep 8, 2026

    71/100
    • ECI—
    • Price$0.04 / $0.15
    • Context260K
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Too close to call

It is close. Our weighted score puts them within 3 points (Mercury 2.5 71/100, Laguna XS 2.1 68/100), so choose by what matters most for your work: Mercury 2.5 on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceMercury 2.5Mercury 2.5 $0.068 · Laguna XS 2.1 $0.075 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameLaguna XS 2.1 262,144 · Mercury 2.5 260,000 tokens
  • Widest inputsSame inputsLaguna XS 2.1: Text · Mercury 2.5: Text
  • Self-hostingLaguna XS 2.1Publishes downloadable weights
How the score is built
MeasureWeightLaguna XS 2.1Mercury 2.5
Price50%100100
Inputs & features30%3545
Context window20%3736
Overall100%68/10071/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Laguna XS 2.1 vs Mercury 2.5 specifications side by side
SpecificationLaguna XS 2.1PoolsideMercury 2.5Inception
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.06$0.04 (best)
Output$0.12 (best)$0.15
Cached input—$0.004
Blended (3:1)$0.075$0.068 (best)
Long-context rateSame rateSame rate
Price sourceMedian of 1 providersOfficial Inception API
Limits
Context window262,144 tokens (best)260,000 tokens
Max output32,768 tokens65,536 tokens (best)
Inputs and features
TextYesYes
ImagesNoNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesYeslow · medium · high
Tool callingYesYes
Structured outputNoYes
Availability
WeightsOpenProprietary
API model IDpoolside/laguna-xs-2.1mercury-2.5
API providers4 (best)1
ReleasedJul 2, 2026Sep 8, 2026
Knowledge cutoff—Nov 1, 2025
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Laguna XS 2.1$0.84
  • Mercury 2.5$0.70
04 — Questions

Which should you choose?

Which is better: Laguna XS 2.1 or Mercury 2.5?

It is close. Our weighted score puts them within 3 points (Mercury 2.5 71/100, Laguna XS 2.1 68/100), so choose by what matters most for your work: Mercury 2.5 on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, Laguna XS 2.1 or Mercury 2.5?

Mercury 2.5 is cheaper at $0.04 input / $0.15 output per million tokens (official Inception API price). Laguna XS 2.1 costs $0.06 input / $0.12 output per million tokens (median across 1 API provider; free on Poolside). At a typical mix of three input tokens to one output token, that is $0.068 per million tokens for Mercury 2.5 versus $0.075 for Laguna XS 2.1 (1.1× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Laguna XS 2.1 has not been scored yet and Mercury 2.5 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Laguna XS 2.1 and Mercury 2.5 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

Their context windows are effectively the same size: Laguna XS 2.1 262,144 and Mercury 2.5 260,000 tokens. Maximum output per response: Laguna XS 2.1 up to 32,768, Mercury 2.5 up to 65,536 tokens.

Which can read images, PDFs, audio or video?

Laguna XS 2.1 accepts text; Mercury 2.5 accepts text. They handle the same number of input types.

Are any of these open source?

Laguna XS 2.1 publishes its weights and can be self-hosted; Mercury 2.5 is proprietary.

Which is newer?

Mercury 2.5 is the newest, released Sep 8, 2026. Laguna XS 2.1 came out Jul 2, 2026. Knowledge cutoff: Mercury 2.5 Nov 1, 2025.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.