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-5.3-CodexvsGPT-6 Sol Pro
Updated Sep 2026

GPT-5.3-CodexvsGPT-6 Sol Pro

GPT-5.3-Codex is cheaper than GPT-6 Sol Pro at $1.75/M vs $2/M input tokens.

GPT-5.3-Codex and GPT-6 Sol Pro compared across 20 shared prompts
SpecGPT-5.3-CodexGPT-6 Sol Pro
Input price$1.75/M tokens$2/M tokens
Output price$14/M tokens$10/M tokens
Context window400K tokens1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedFeb 2026Sep 2026
Side by side

Same prompt, both answers

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

Startup Pitch Teardown

Here's a pitch deck summary for a startup called "MindMeld AI": **Slide 1 - Vision:** "We're building the future of human-AI collaboration.…

GPT-5.3-Codex429 words
Great concept, but three claims stand out as especially weak from an investor diligence perspective: “MindMeld AI reads your brainwaves to predict what you want to type before you think it.” (Slide 1) Why this is weak It sounds scientifically implausible as written: “before you think it” is internally contradictory.
Read the full answer
GPT-6 Sol Pro347 words
The three weakest claims are the product’s decoding performance, the market size, and the evidence offered to support the proposed valuation. Claim Why it’s weak How to strengthen it “Our EEG headband decodes neural patterns into text with 94% accuracy. Works with any language, any device.”
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-5.3-Codex485 words
Absolutely—great goal. Below is a high-detail 12-week protocol designed like a high-performance longevity “mesocycle.” I’ll keep it practical, measurable, and advanced—but still safe. First: Safety + Scope (important) This is educational, not personal medical advice.
Read the full answer
GPT-6 Sol Pro1,411 words
A 12-week longevity and performance plan Aim: improve the health markers most strongly linked to long-term outcomes—cardiorespiratory fitness, strength, blood pressure, metabolic health, sleep, and sustainable habits—while testing whether more experimental “biohacks” add anything useful.
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-5.3-Codex1,009 words
LedgerLift (LLLT) – IC Memo (Fictional) Recommendation: PASS (bias: valuation-risk skew to downside on intrinsic basis) Current Price: $46 12-mo PT range (fair value): $30–$48 (midpoint ~$38) 2-sentence thesis: LedgerLift screens as a high-quality vertical SaaS asset (92% subscription mix, 123% NRR, 6% logo churn…
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

Michelin Star Recipe Design

Design an innovative recipe for a multi-component dish worthy of a Michelin 3-star restaurant. The recipe should feature an unusual…

GPT-5.3-Codex970 words
Dish Concept: “Forest Tide” Koji-cured venison loin, glazed venison cheek, sea urchin royale, charred celeriac, blackcurrant–shiso gastrique, and buckwheat-cacao tuile Narrative This dish is built around a deliberate tension: deep, iron-rich game (forest) against sweet-briny sea urchin (tide).
Read the full answer
GPT-6 Sol Pro913 words
Scallop, Green Strawberry & White Chocolate Seared scallops with charred kohlrabi, compressed green strawberry, white-chocolate–miso beurre blanc, kombu oil and buckwheat lace The unusual pairing is scallop and white chocolate.
Read the full answer

Ethical Dilemma with Stakeholders

You're the CEO of a pharmaceutical company. Your best-selling drug ($2B annual revenue, used by 4 million patients for chronic pain) has…

GPT-5.3-Codex915 words
I would not wait. This is a textbook “patient safety + material disclosure” crisis. The right move is rapid, documented, regulator-first action. Immediate stance (set at Hour 0) Patient safety first (interim risk controls now, not after perfect certainty).
Read the full answer
GPT-6 Sol Pro1,450 words
I would treat this as a credible, urgent safety signal, not as a finding that can wait six months for a completed regulatory submission. The estimate—liver failure in roughly 1 in 8,000 patients over five years—needs validation, but the outcome is severe and the current warning omits it.
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-5.3-Codex1,188 words
Great prompt. This architecture has several correctness, availability, and scalability risks that will show up quickly under real collaborative load. Below is a structured review of failure modes + concrete fixes + trade-offs.
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
Our Verdict
GPT-5.3-Codex
GPT-5.3-Codex
GPT-6 Sol Pro
GPT-6 Sol Pro

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

GPT-5.3-Codex
Input
$1.75
1.1× cheaper
Output
$14.00
GPT-6 Sol Pro
Input
$2.00
Output
$10.00
1.4× cheaper

GPT-5.3-Codex wins input (1.1× cheaper)·GPT-6 Sol Pro wins output (1.4× cheaper)

Where to run it

4 hosts

GPT-5.3-Codex2 hosts
HostInOutContextUptime
Azure AI Foundry$1.75 in·$14.00 out·400k·100% upOpenAI$1.75 in·$14.00 out·400k·100% up
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-5.3-Codex has a 400K 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-5.3-Codex 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-5.3-Codex costs $1.75/M input tokens and GPT-6 Sol Pro costs $2/M input tokens. GPT-5.3-Codex is $0.25/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-5.3-Codex 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-5.3-Codex logoSolar Mini 4 logo
GPT-5.3-Codex 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-5.3-Codex logoGLM 5.3 Prime logo
GPT-5.3-Codex 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-5.3-Codex logoCommand A+ logo
GPT-5.3-Codex 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-5.3-Codex logoGPT-6 Luna Pro logo
GPT-5.3-Codex 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-5.3-Codex logoGPT-6 Luna logo
GPT-5.3-Codex vs GPT-6 LunaSame lab
GPT-5.3-Codex logoGPT-6 Sol logo
GPT-5.3-Codex 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-5.3-Codex logoGemini 3.1 Flash Lite logo
GPT-5.3-Codex vs Gemini 3.1 Flash LiteNew provider
GPT-5.3-Codex logoGemini 3.1 Flash Lite Preview logo
GPT-5.3-Codex vs Gemini 3.1 Flash Lite PreviewNew provider
GPT-5.3-Codex logoGemini 3.1 Pro Preview logo
GPT-5.3-Codex vs Gemini 3.1 Pro PreviewSame size
GPT-5.3-Codex logoGemini 3.5 Flash logo
GPT-5.3-Codex vs Gemini 3.5 FlashNew provider

Model pages

GPT-5.3-Codex logo
GPT-5.3-Codex53 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