What is the difference between DeepSeek V4 Pro and Laguna S 2.1 (free)?

DeepSeek V4 Pro is developed by DeepSeek while Laguna S 2.1 (free) is developed by Poolside. DeepSeek V4 Pro has a 1.0M 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, DeepSeek V4 Pro or Laguna S 2.1 (free)?

It depends on your use case. DeepSeek V4 Pro 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 DeepSeek V4 Pro cost compared to Laguna S 2.1 (free)?

DeepSeek V4 Pro costs $1.74/M input tokens and Laguna S 2.1 (free) costs $0/M input tokens. Laguna S 2.1 (free) is $1.74/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 DeepSeek V4 Pro and Laguna S 2.1 (free) on Rival?

This page shows a side-by-side comparison of DeepSeek V4 Pro 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

DeepSeek V4 ProvsLaguna S 2.1 (free)

Laguna S 2.1 (free) is cheaper than DeepSeek V4 Pro at $0/M vs $1.74/M input tokens.

DeepSeek V4 Pro and Laguna S 2.1 (free) compared across 10 shared prompts
Spec	DeepSeek V4 Pro	Laguna S 2.1 (free)
Input price	$1.74/M tokens	Free
Output price	$3.48/M tokens	Free
Context window	1.0M tokens	262K tokens
Weights	Open	—
Free API (OpenRouter)	No	Yes (1 provider)
Released	Apr 2026	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…

DeepSeek V4 Pro1,917 words

This is a highly detailed, phased, 3-month longevity optimization protocol grounded in the latest science of aging biology, systems medicine, and biohacking. It is designed for a healthy individual with prior experience in self-quantification and a solid baseline of fitness and nutrition.

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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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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…

DeepSeek V4 Pro1,098 words

INTERNAL MEMO – INVESTMENT COMMITTEE To: IC Members From: Research Team Date: Today Re: LedgerLift (LLLT) – Initiation Recommendation Action: Short LLLT 12-Month Price Target: $28–$38 (Base DCF $28; Comps-blend ~$36) Thesis: LedgerLift’s premium multiple (37x NTM EBIT) prices in a “perfect deceleration” that our DCF…

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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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Adversarial Contract Review

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

DeepSeek V4 Pro2,250 words

Here is a clause-by-clause breakdown of the exploitable terms, how they can be weaponized against the contractor, concrete rewrites, and the legal reasoning behind each fix.

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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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Our Verdict

DeepSeek V4 Pro

Laguna S 2.1 (free)Runner-up

Not enough votes to call it. On the specs, DeepSeek V4 Pro has the edge: bigger model tier, bigger context window, major provider backing.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

DeepSeek V4 Pro

Input

$1.74

Output

$3.48

Laguna S 2.1 (free)

Input

$0.000

Output

$0.000

Where to run it

16 hosts, cheapest first

DeepSeek V4 Pro15 hosts

HostInOutContextUptime

StreamLakefp8$0.93 in$1.87 out1M99% up Baidu Qianfanfp8$0.94 in$1.87 out1M99.8% up GMI Cloudfp8$0.96 in$1.91 out1M99.8% up DigitalOcean$1.04 in$2.09 out1M100% up Cloudflare Workers AI$1.15 in$2.55 out1M96.1% up DeepInfrafp8$1.30 in$2.60 out1M99.3% up

9 more hosts

Alibaba Cloudfp8$1.42 in$2.83 out1M100% up SiliconFlowfp8$1.50 in$3.13 out1M99.5% up Novitafp8$1.60 in$3.20 out1M100% up Venice$1.65 in$3.30 out1M96.1% up AtlasCloudfp4$1.68 in$3.38 out1M99.9% up Basetenfp4$1.74 in$3.48 out1M99.5% up NextBitfp8$1.74 in$3.48 out1M98% up Parasailfp8$1.74 in$3.48 out1M99.1% up Azure AI Foundry$1.91 in$3.83 out1M94.8% up

Laguna S 2.1 (free)1 host

HostInOutContextUptime

Poolsidefp4$0 in$0 out262k99.9% up

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

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