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-5.5vsGPT-6 Sol Pro
Updated Sep 2026

GPT-5.5vsGPT-6 Sol Pro

GPT-6 Sol Pro is cheaper than GPT-5.5 at $2/M vs $5/M input tokens.

GPT-5.5 and GPT-6 Sol Pro compared across 20 shared prompts
SpecGPT-5.5GPT-6 Sol Pro
Input price$5/M tokens$2/M tokens
Output price$30/M tokens$10/M tokens
Context window1.1M tokens1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedApr 2026Sep 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 20 prompts both answered. Formatting stripped, words untouched.

Beginner's Longevity Plan

Outline a simple, actionable 1-month plan for someone starting their journey towards better health and longevity. Focus on 3 key areas…

GPT-5.5615 words
Here’s a simple 1-month beginner-friendly plan focused on three high-impact areas for better health and longevity: nutrition, movement, and sleep/recovery. If you have a medical condition, take medications, or haven’t exercised in a while, consider checking with a healthcare professional first.
Read the full answer
GPT-6 Sol Pro230 words
A simple 1-month health plan Focus on food, movement, and sleep. Start small enough that you can repeat the habits most days. Week Food Movement Sleep 1: Set a baseline Add a fruit or vegetable to one meal each day. Walk for 10 minutes, 4 days this week. Pick a consistent wake-up time.
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-5.51,055 words
LedgerLift (LLLT) IC Memo — Fictional Recommendation: Pass / Watchlist Current price: $46 Market cap: $8.7B; EV: $7.3B after $1.4B net cash 12-month fair value range: $40–$50/share Thesis, 2 sentences: LedgerLift is a high-quality mid-market spend management/AP automation SaaS asset with 92% subscription revenue, 123%…
Read the full answer
GPT-6 Sol Pro974 words
LedgerLift (LLLT) — Investment Committee Memo Recommendation: Short 12-month price target: $30–$44 Thesis. LedgerLift has attractive subscription economics, but at $46 the stock prices in substantially more durable cash flow than the supplied operating assumptions produce: base-case DCF value is about $28 per share…
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-5.53,819 words
Below is a comprehensive review of the architecture’s likely failure modes, race conditions, and scaling bottlenecks, with concrete mitigations and trade-offs. Real-time Synchronization Problems 1.1 Broadcasting only to clients on the same server Problem Each API server only broadcasts WebSocket changes to clients…
Read the full answer
GPT-6 Sol Pro1,277 words
The central problem is that this design treats concurrent edits as independent database writes, then tries to reconcile them with client timestamps. That can lose valid edits even when every component is working.
Read the full answer

Mini LBO Underwrite

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

GPT-5.5563 words
Key assumptions Entry closes at end of FY2025; exit at end of FY2030. Interest is calculated on beginning-of-year debt balances. Term Loan amortization = 1.0% of original Term Loan principal = $4.8m/year. Mezz PIK = 2.0% of beginning-of-year Mezz balance, added to principal annually.
Read the full answer
GPT-6 Sol Pro331 words
HarborTech Services — simplified LBO ($m) Entry: Enterprise value = 12.0 × $120 = $1,440. Fees are $28.8; opening debt is a $480 term loan plus $180 mezzanine loan. Initial equity = $1,440 + $28.8 − $660 = $808.8. Interest is calculated on beginning-of-year balances.
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-5.52,391 words
Not legal advice; contract enforceability depends heavily on jurisdiction and facts. A contractor should have a lawyer review this before signing. That said, this draft is heavily one-sided and contains multiple clauses that could be exploited against the contractor.
Read the full answer
GPT-6 Sol Pro970 words
This is a strongly one-sided draft. Do not sign it as written. The enforceability of particular terms—especially the non-compete, payment provisions, and arbitration clause—depends on the governing jurisdiction, which the agreement does not identify.
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-5.53,386 words
A transistor invented in 1920 would not simply move the entire digital age back by 27 years. The transistor depended on related capabilities: purified germanium and silicon, crystal growth, quantum/solid-state theory, precision metallurgy, photolithography, clean rooms, statistical quality control, and a large market…
Read the full answer
GPT-6 Sol Pro876 words
A transistor invented in 1920 would not put 1970s computers in the hands of WWII generals. The crucial question is whether it was merely demonstrated or could also be manufactured reliably.
Read the full answer
Our Verdict
GPT-5.5
GPT-5.5
GPT-6 Sol Pro
GPT-6 Sol Pro

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

GPT-6 Sol Pro costs 3.0x less per token.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-5.5
Input
$5.00
Output
$30.00
GPT-6 Sol Pro
Input
$2.00
2.5× cheaper
Output
$10.00
3.0× cheaper

GPT-6 Sol Pro is cheaper on both: 2.5× input, 3.0× output.

Where to run it

5 hosts, cheapest first

GPT-5.53 hosts
HostInOutContextUptime
Azure AI Foundry$5.00 in·$30.00 out·1.1M·99.9% upOpenAI$5.00 in·$30.00 out·1.1M·99.9% upAmazon Bedrock$5.50 in·$33.00 out·1.1M—
GPT-6 Sol Pro2 hosts
HostInOutContextUptime
Azure AI Foundry$2.00 in·$10.00 out·1.1M·99.9% upOpenAI$2.00 in·$10.00 out·1.1M·100% up

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

Research

What we learned reading every model

FAQ

Common questions

Both are developed by OpenAI but target different use cases. GPT-5.5 has a 1.1M token context window vs GPT-6 Sol Pro's 1.1M. You can compare their actual outputs across 20 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-5.5 and GPT-6 Sol Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 20 challenges so you can judge which fits your needs best.

GPT-5.5 costs $5/M input tokens and GPT-6 Sol Pro costs $2/M input tokens. GPT-6 Sol Pro 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.

This page shows a side-by-side comparison of GPT-5.5 and GPT-6 Sol Pro 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-5.5 logoSolar Mini 4 logo
GPT-5.5 vs Solar Mini 4Landed Sep 2026
GPT-6 Sol Pro logoQwen3.8 Max Prime logo
GPT-6 Sol Pro vs Qwen3.8 Max PrimeLanded Sep 2026
GPT-5.5 logoGLM 5.3 Prime logo
GPT-5.5 vs GLM 5.3 PrimeLanded Sep 2026
GPT-6 Sol Pro logoQwen3.8 Omni Flash logo
GPT-6 Sol Pro vs Qwen3.8 Omni FlashLanded Sep 2026
GPT-5.5 logoCommand A+ logo
GPT-5.5 vs Command A+Landed Sep 2026
GPT-6 Sol Pro logoClaude Opus 5.5 logo
GPT-6 Sol Pro vs Claude Opus 5.5Landed Sep 2026
GPT-5.5 logoGPT-6 Luna Pro logo
GPT-5.5 vs GPT-6 Luna ProLanded Sep 2026
GPT-6 Sol Pro logoGPT-6 Luna logo
GPT-6 Sol Pro vs GPT-6 LunaLanded Sep 2026

Same lab, same size, long tail

GPT-5.5 logoGPT-6 Luna logo
GPT-5.5 vs GPT-6 LunaSame lab
GPT-5.5 logoGPT-6 Sol logo
GPT-5.5 vs GPT-6 SolSame lab
GPT-6 Sol Pro logoGPT-6 Luna Pro logo
GPT-6 Sol Pro vs GPT-6 Luna ProSame lab
GPT-6 Sol Pro logoGPT-6 Sol logo
GPT-6 Sol Pro vs GPT-6 SolSame lab
GPT-5.5 logoHorizon Alpha logo
GPT-5.5 vs Horizon AlphaNew provider
GPT-5.5 logoHorizon Beta logo
GPT-5.5 vs Horizon BetaNew provider
GPT-6 Sol Pro logoHunter Alpha logo
GPT-6 Sol Pro vs Hunter AlphaNew provider
GPT-5.5 logoHy3 logo
GPT-5.5 vs Hy3Same size

Model pages

GPT-5.5 logo
GPT-5.558 outputs, specs and price
GPT-6 Sol Pro logo
GPT-6 Sol Pro20 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