What is the difference between Claude Sonnet 4 and Laguna S 2.1 (free)?

Claude Sonnet 4 is developed by Anthropic while Laguna S 2.1 (free) is developed by Poolside. Claude Sonnet 4 has a 200K token context window vs Laguna S 2.1 (free)'s 262K. You can compare their actual outputs across 10 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4 or Laguna S 2.1 (free)?

It depends on your use case. Claude Sonnet 4 and Laguna S 2.1 (free) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 10 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4 cost compared to Laguna S 2.1 (free)?

Claude Sonnet 4 costs $3/M input tokens and Laguna S 2.1 (free) costs $0/M input tokens. Laguna S 2.1 (free) is $3.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Claude Sonnet 4 and Laguna S 2.1 (free) on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4 and Laguna S 2.1 (free) across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Updated Jul 2026

Claude Sonnet 4vsLaguna S 2.1 (free)

Laguna S 2.1 (free) is cheaper than Claude Sonnet 4 at $0/M vs $3/M input tokens.

Claude Sonnet 4 and Laguna S 2.1 (free) compared across 10 shared prompts
Spec	Claude Sonnet 4	Laguna S 2.1 (free)
Input price	$3/M tokens	Free
Output price	$15/M tokens	Free
Context window	200K tokens	262K tokens
Weights	Closed	—
Free API (OpenRouter)	No	Yes (1 provider)
Released	May 2025	Jul 2026

Side by side

Same prompt, both answers

Opening lines from 3 of the 10 prompts both answered. Formatting stripped, words untouched.

Advanced Longevity Plan (Biohacker)

Develop a comprehensive, cutting-edge 3-month longevity plan for a biohacker aiming to optimize longevity, physical and cognitive…

Claude Sonnet 41,028 words

The Comprehensive 3-Month Longevity Optimization Protocol Overview & Foundation This protocol integrates cutting-edge biohacking strategies with evidence-based longevity research. Each com ponent is designed to work synergistically for maximum healthspan and performance optimization.

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Laguna S 2.1 (free)1,140 words

Comprehensive 3-Month Longevity Optimization Plan Phase 1: Foundation & Assessment (Month 1) Week 1-2: Baseline Establishment Comprehensive Health Testing Complete blood panel (CBC, CMP, lipid panel, inflammatory markers: hs-CRP, IL-6) Hormone panel (testosterone, estrogen, DHEA, cortisol, thyroid panel) Genetic…

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Adversarial Contract Review

Here is a contract for a software consulting engagement: --- SOFTWARE CONSULTING AGREEMENT This Agreement is entered into between TechCorp…

Claude Sonnet 4277 words

This contract is heavily skewed against the contractor with multiple exploitative clauses. Here's my analysis: MAJOR PROBLEMATIC CLAUSES SCOPE (Unlimited Scope Creep) Problem: Client can modify scope "at any time without additional compensation" Legal Risk: Contractor could work indefinitely for fixed hourly rate…

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Laguna S 2.1 (free)275 words

I'll analyze each clause for potential exploitation against the contractor and suggest improvements. Exploitable Clauses & Recommended Modifications SCOPE CLAUSE Problem: "Client reserves the right to modify the scope at any time without additional compensation" Allows unlimited scope creep without extra pay No…

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Advanced Investment Memo (IC Memo)

You are writing an internal investment committee memo for a long/short equity fund. Company (fictional): LedgerLift (ticker: LLLT) – B2B…

Claude Sonnet 4754 words

INVESTMENT COMMITTEE MEMO Company: LedgerLift (LLLT) - B2B Spend Management & AP Automation SaaS Current Price: $46.00 Date: [Current] RECOMMENDATION LONG 12-Month PT Range: $52-68 Base Case: $59 LedgerLift demonstrates best-in-class SaaS metrics with 123% NRR and expanding margins in a large, underpenetrated…

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Laguna S 2.1 (free)910 words

INTERNAL INVESTMENT COMMITTEE MEMO 1. Recommendation & Thesis Recommendation: LONG 12-Month Price Target Range: $62 – $75/share Thesis: LedgerLift is a high-quality B2B SaaS platform with strong recurring revenue, exceptional unit economics, and durable customer retention.

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Our Verdict

Claude Sonnet 4

Laguna S 2.1 (free)

Not enough votes to call it. On the specs, nothing separates them.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Claude Sonnet 4

Input

$3.00

Output

$15.00

Laguna S 2.1 (free)

Input

$0.000

Output

$0.000

Where to run it

2 hosts

Claude Sonnet 41 host

HostInOutContextUptime

Amazon Bedrock$3.00 in$15.00 out200k100% up

Laguna S 2.1 (free)1 host

HostInOutContextUptime

Poolsidefp4$0 in$0 out262k100% up

Per million tokens. Prices and uptime via OpenRouter, checked 22 Sep 2026.

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