Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed
  1. Home
  2. /
  3. Compare
  4. /
  5. GPT-5.4 ProvsSolar Mini 4
Updated Sep 2026

GPT-5.4 ProvsSolar Mini 4

Solar Mini 4 is cheaper than GPT-5.4 Pro at $0.05/M vs $30/M input tokens.

GPT-5.4 Pro and Solar Mini 4 compared across 17 shared prompts
SpecGPT-5.4 ProSolar Mini 4
Input price$30/M tokens$0.05/M tokens
Output price$180/M tokens$0.2/M tokens
Context window1.1M tokens524K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedMar 2026Sep 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 17 prompts both answered. Formatting stripped, words untouched.

Mini LBO Underwrite

You are underwriting a 5-year LBO for a private equity investment committee. Company (fictional): HarborTech Services (HTS) –…

GPT-5.4 Pro731 words
Below is a simplified LBO build for HarborTech Services (HTS). All figures in $m unless noted. Rounding: tables are rounded; IRR/MOIC use unrounded math. Entry / Sources & Uses FY2025 EBITDA: 120.0 Purchase price: 12.0x EBITDA → Enterprise value = 12.0 × 120.0 = 1,440.0 Transaction fees: 2.0% of EV → 28.8 Total uses =…
Read the full answer
Solar Mini 41,718 words
518.51935 New TL: 276.34682 - 86.82747 = 189.51935 Mezz: PIK 194.8377888 * 0.02 = 3.896755776 New Mezz: 194.8377888 + 3.896755776 = 198.734544576 Ending Balances: TL: 189.52 Mezz: 198.73 Total Debt: 388.25 Exit (End of FY2030): Exit EBITDA: 206.6252668 Exit Multiple: 10.5x Exit EV: 206.6252668 * 10.5 = 2,169.5653014…
Read the full answer

Historical Counterfactual Analysis

If the transistor had been invented in 1920 instead of 1947, trace the likely technological, economic, and geopolitical implications through…

GPT-5.4 Pro2,183 words
Most likely, a transistor invented in 1920 would move the electronics/computing frontier forward by about 10–15 years by 1980, not the full 27 years. Reason: the transistor alone is not enough; you also need high-purity materials, crystal growth, photolithography, test equipment, software, batteries, precision…
Read the full answer
Solar Mini 41,539 words
This is a fascinating counterfactual. I need to note upfront that the scientific and engineering foundations for a working transistor did not exist in 1920. Quantum mechanics was barely a decade old, band theory of solids hadn't been developed, and semiconductor physics (doping, p-n junctions, electron mobility) was…
Read the full answer

Debug This Architecture

Here's the architecture for a real-time collaborative document editor (like Google Docs): **System Overview:** - Frontend: React SPA with…

GPT-5.4 Pro2,331 words
This architecture will work for a demo, but it has major correctness, latency, and security problems for a Google-Docs-like editor. Highest-risk flaws Client-clock last-write-wins will lose edits and can be gamed by bad clocks.
Read the full answer
Solar Mini 41,165 words
Here’s a systematic breakdown of the architectural weaknesses, failure modes, and scaling bottlenecks in your design, along with specific solutions and their trade-offs. Real-Time Synchronization & WebSocket Affinity Issue: Round-robin load balancing is stateless, but WebSockets are stateful and long-lived.
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-5.4 Pro1,064 words
LedgerLift (LLLT) — IC Memo Recommendation: Pass 12-month PT range: $40–$47 2-sentence thesis: LedgerLift looks like a good business but only an average stock here: retention is strong (94% GRR, 123% NRR), the model is mostly subscription, and margins are inflecting, but at $46 the shares already discount a lot of the…
Read the full answer
Solar Mini 4347 words
Investment Committee Memo: LedgerLift (LLLT) To: Investment Committee From: Research Date: October 26, 2023 Subject: Long/Short Recommendation: LedgerLift (LLLT) Recommendation Action: Long 12-Month PT Range: $55 – $65 Thesis: LedgerLift demonstrates best-in-class SaaS metrics (123% NRR, 94% gross retention) within a…
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-5.4 Pro1,392 words
This agreement is heavily client-favored. Every numbered clause has language that could be used against the contractor. Short version: I would not sign it without major redlines to Clauses 1–9, especially 2, 3, 4, 5, 6, and 7. Below is a clause-by-clause review.
Read the full answer
Solar Mini 41,994 words
This agreement contains several provisions that are heavily one-sided, overly broad, or legally vulnerable. Below is a clause-by-clause analysis of the most exploitable terms, suggested modifications, and the legal reasoning behind them. Note: Contract law varies significantly by jurisdiction.
Read the full answer

Advanced Longevity Plan (Biohacker)

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

GPT-5.4 Pro2,426 words
Below is a 12-week, high-performance longevity protocol designed for a healthy biohacker who wants to improve lifespan-relevant markers, physical performance, and cognitive output at the same time. Use it as a data-driven template, not dogma.
Read the full answer
Solar Mini 41,388 words
🧬 3-Month Biohacker Longevity & Performance Optimization Plan ⚠️ Important Disclaimer: This protocol is for informational and educational purposes. It is not medical advice. Always consult a licensed healthcare provider before starting new supplements, fasting regimens, intense exercise, or neurofeedback protocols.
Read the full answer
Our Verdict
GPT-5.4 Pro
GPT-5.4 Pro
Solar Mini 4
Solar Mini 4Runner-up

Not enough votes to call it. On the specs, GPT-5.4 Pro has the edge: bigger model tier, bigger context window, major provider backing.

Solar Mini 4 costs 900x less per token.

Too close to call
API pricing

Cost per 1M tokens

GPT-5.4 Pro
Input
$30.00
Output
$180.00
Solar Mini 4
Input
$0.05
600× cheaper
Output
$0.20
900× cheaper

Solar Mini 4 is cheaper on both: 600× input, 900× output.

Where to run it

3 hosts

GPT-5.4 Pro2 hosts
HostInOutContextUptime
Azure AI Foundry$30.00 in·$180.00 out·1.1M—OpenAI$30.00 in·$180.00 out·1.1M·99.9% up
Solar Mini 41 host
HostInOutContextUptime
UUpstage$0.05 in·$0.20 out·524k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 25 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

GPT-5.4 Pro is developed by OpenAI while Solar Mini 4 is developed by Upstage. GPT-5.4 Pro has a 1.1M token context window vs Solar Mini 4's 524K. You can compare their actual outputs across 17 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-5.4 Pro and Solar Mini 4 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 17 challenges so you can judge which fits your needs best.

GPT-5.4 Pro costs $30/M input tokens and Solar Mini 4 costs $0.05/M input tokens. Solar Mini 4 is $29.95/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of GPT-5.4 Pro and Solar Mini 4 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.

Keep exploring

More comparisons

Against the newest arrivals

GPT-5.4 Pro logoQwen3.8 Max Prime logo
GPT-5.4 Pro vs Qwen3.8 Max PrimeLanded Sep 2026
Solar Mini 4 logoGLM 5.3 Prime logo
Solar Mini 4 vs GLM 5.3 PrimeLanded Sep 2026
GPT-5.4 Pro logoQwen3.8 Omni Flash logo
GPT-5.4 Pro vs Qwen3.8 Omni FlashLanded Sep 2026
Solar Mini 4 logoCommand A+ logo
Solar Mini 4 vs Command A+Landed Sep 2026
GPT-5.4 Pro logoClaude Opus 5.5 logo
GPT-5.4 Pro vs Claude Opus 5.5Landed Sep 2026
Solar Mini 4 logoGPT-6 Luna Pro logo
Solar Mini 4 vs GPT-6 Luna ProLanded Sep 2026
GPT-5.4 Pro logoGPT-6 Sol Pro logo
GPT-5.4 Pro vs GPT-6 Sol ProLanded Sep 2026
Solar Mini 4 logoGPT-6 Luna logo
Solar Mini 4 vs GPT-6 LunaLanded Sep 2026

Same lab, same size, long tail

GPT-5.4 Pro logoGPT-5.4 logo
GPT-5.4 Pro vs GPT-5.4Version compare
GPT-5.4 Pro logoGPT-6 Luna Pro logo
GPT-5.4 Pro vs GPT-6 Luna ProSame lab
Solar Mini 4 logoSolar Pro 4 logo
Solar Mini 4 vs Solar Pro 4Same lab
Solar Mini 4 logoSolar Pro 3 logo
Solar Mini 4 vs Solar Pro 3Same lab
GPT-5.4 Pro logoMercury 2.5 logo
GPT-5.4 Pro vs Mercury 2.5New provider
GPT-5.4 Pro logoMercury 2.5 Preview logo
GPT-5.4 Pro vs Mercury 2.5 PreviewNew provider
Solar Mini 4 logoMiMo-V2-Flash logo
Solar Mini 4 vs MiMo-V2-FlashNew provider
Solar Mini 4 logoMiMo-V2-Omni logo
Solar Mini 4 vs MiMo-V2-OmniNew provider

Model pages

GPT-5.4 Pro logo
GPT-5.4 Pro18 outputs, specs and price
Solar Mini 4 logo
Solar Mini 419 outputs, specs and price
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed