What is the difference between GPT-5.4 and Laguna S 2.1 (free)?

GPT-5.4 is developed by OpenAI while Laguna S 2.1 (free) is developed by Poolside. GPT-5.4 has a 1.1M 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, GPT-5.4 or Laguna S 2.1 (free)?

It depends on your use case. GPT-5.4 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 GPT-5.4 cost compared to Laguna S 2.1 (free)?

GPT-5.4 costs $2.5/M input tokens and Laguna S 2.1 (free) costs $0/M input tokens. Laguna S 2.1 (free) is $2.50/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 GPT-5.4 and Laguna S 2.1 (free) on Rival?

This page shows a side-by-side comparison of GPT-5.4 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

GPT-5.4vsLaguna S 2.1 (free)

Laguna S 2.1 (free) is cheaper than GPT-5.4 at $0/M vs $2.5/M input tokens.

GPT-5.4 and Laguna S 2.1 (free) compared across 10 shared prompts
Spec	GPT-5.4	Laguna S 2.1 (free)
Input price	$2.5/M tokens	Free
Output price	$15/M tokens	Free
Context window	1.1M tokens	262K tokens
Weights	Closed	—
Free API (OpenRouter)	No	Yes (1 provider)
Released	Mar 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…

GPT-5.42,946 words

Below is a high-level, educational 12-week framework for “longevity-oriented performance optimization.” It is not medical advice and shouldn’t replace care from a physician, especially because some interventions biohackers use can interact with medications, affect liver/kidney function, sleep, mood, blood pressure…

Read the full answer

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…

Read the full answer

Adversarial Contract Review

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

GPT-5.42,522 words

Here are the main contractor-unfriendly clauses, why they’re risky, and concrete redlines you should consider. This is business/legal information, not legal advice; for an actual engagement, a lawyer in the relevant jurisdiction should review it.

Read the full answer

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…

Read the full answer

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…

GPT-5.41,307 words

LedgerLift (LLLT) — Internal IC Memo Recommendation: Long Current Price: $46 12-month PT range: $58–$74 (base-centered fair value ~$66; downside ~$47; upside ~$86 on DCF, but we cap 12-month bull PT at $74 to reflect execution/rating risk) Two-sentence thesis: LedgerLift screens as a high-quality vertical SaaS/fintech…

Read the full answer

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.

Read the full answer

Our Verdict

GPT-5.4

Laguna S 2.1 (free)Runner-up

Not enough votes to call it. On the specs, GPT-5.4 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

GPT-5.4

Input

$2.50

Output

$15.00

Laguna S 2.1 (free)

Input

$0.000

Output

$0.000

Where to run it

4 hosts, cheapest first

GPT-5.43 hosts

HostInOutContextUptime

Azure AI Foundry$2.50 in$15.00 out1.1M100% up OpenAI$2.50 in$15.00 out1.1M100% up Amazon Bedrock$2.75 in$16.50 out1.1M—

Laguna S 2.1 (free)1 host

HostInOutContextUptime

Poolsidefp4$0 in$0 out262k100% up

Per million tokens. Prices and uptime via OpenRouter, checked 23 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons