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  5. Claude Sonnet 4.5vsSeed 2.1 Turbo
Updated Aug 2026

Claude Sonnet 4.5vsSeed 2.1 Turbo

Seed 2.1 Turbo is cheaper than Claude Sonnet 4.5 at $0.5/M vs $3/M input tokens.

Claude Sonnet 4.5 and Seed 2.1 Turbo compared across 42 shared prompts
SpecClaude Sonnet 4.5Seed 2.1 Turbo
Input price$3/M tokens$0.5/M tokens
Output price$15/M tokens$2.5/M tokens
Context window200K tokens262K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedSep 2025Aug 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 42 prompts both answered. Formatting stripped, words untouched.

Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

Claude Sonnet 4.5165 words
Golden Pantry Frittata Ingredients: 6 eggs 1 cup shredded cheese (cheddar or mozzarella) 1 onion, diced 2 cloves garlic, minced 2 tablespoons olive oil Salt and pepper to taste 1/2 teaspoon dried herbs (oregano, basil, or Italian seasoning) Instructions: Preheat your oven to 375°F (190°C).
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Seed 2.1 Turbo432 words
Dish Name: Pantry Lava Chickpea Crisp A cozy, savory one-skillet meal with bubbly garlicky tomato sauce studded with crispy chickpeas, topped with a crunchy spiced oat crumble. Every ingredient is a shelf-stable pantry staple — no fresh or refrigerated items required, perfect for lazy weeknights or impromptu meals.
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Character Voice Test

Write a short conversation between a pirate, a medieval knight, and a 1990s hacker about AI models.

Claude Sonnet 4.5197 words
An Unlikely Trio Discusses AI Sir Galahad: By my honor, what manner of sorcery be these "AI models" thou speakest of? Captain Redbeard: Arrr, 'tis like havin' a parrot that knows more than just "pieces of eight," matey! But this bird be made o' lightning and numbers instead o' feathers!
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Seed 2.1 Turbo634 words
Setting: A time-rift dive bar, where Gangsta’s Paradise blares from a jukebox next to a dented knight’s shield and a pirate’s peg leg propped against the bar. Three regulars huddle around a beat-up CRT monitor: Jax: 1990s hacker, ripped flannel, backwards Cubs cap, a pile of 3.5” floppies spilling out of his backpack…
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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…

Claude Sonnet 4.51,440 words
48-Hour Crisis Action Plan HOUR 0-2: Immediate Containment & Fact Verification Actions: Convene emergency meeting with Chief Medical Officer, General Counsel, Head of Regulatory Affairs, and Chief Scientific Officer Demand written summary of findings: statistical confidence, causality assessment, comparison to baseline…
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Seed 2.1 Turbo2,370 words
48-Hour Action Plan: Pharmaceutical Drug Safety Crisis Timeline Anchor: T=0 = 9:00 AM Monday, immediately after the internal research team (IRT) confirms a statistically significant 1-in-8,000 5-year liver failure risk for the company’s top-selling chronic pain drug. T+48 = 9:00 AM Wednesday, scheduled board meeting.
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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…

Claude Sonnet 4.5331 words
Your 1-Month Health & Longevity Kickstart Plan 3 Key Areas to Transform 1. NUTRITION: Build Your Foundation Week 1-2: Add Before You Subtract Drink 8 glasses of water daily (set phone reminders) Add 1 serving of vegetables to lunch and dinner Eat protein with every meal (eggs, fish, chicken, beans, yogurt) Week 3-4…
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Seed 2.1 Turbo1,433 words
1-Month Beginner Longevity Plan Who This Is For People with zero consistent health routine, busy schedules, no gym access, and no desire for restrictive diets or extreme changes. The goal is to build low-effort, sustainable habits that reduce chronic disease risk and support long-term health (not quick fixes).
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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.…

Claude Sonnet 4.5503 words
3 Weakest Claims in MindMeld AI's Pitch "94% accuracy" for EEG-based text prediction (Slide 3) Why it's weak: Current state-of-the-art EEG-based BCIs achieve ~10-20 words per minute for direct typing, with significantly lower accuracy than 94% for general text prediction EEG has inherent limitations: low spatial…
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Seed 2.1 Turbo1,137 words
The 3 Weakest Claims in the MindMeld AI Pitch Below are the most problematic claims, ranked by their severity, logical flaws, and impact on investor credibility, along with concrete fixes: Weak Claim: $180B Total Addressable Market (TAM) (Slide 4) The claim: "The BCI market is projected to reach $5.3B by 2030 (Grand…
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Generate a Stand-Up Routine

Write a 3-minute stand-up comedy routine that isn't based on puns.

Claude Sonnet 4.5735 words
"ADULTING IS A SCAM" [Walking on stage] So I turned 35 last month, and I've realized something important: adulting is a scam. It's a pyramid scheme, and our parents are the ones who recruited us. You know what nobody tells you about being an adult? How much TIME you spend just... waiting for repair people.
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Seed 2.1 Turbo563 words
3-Minute Stand-Up Routine (no puns, timed for natural delivery + laugh pauses) (Walks on stage, leans into the mic, deadpan, scans the crowd) 0:00 “Raise your hand if you’ve ever bought a houseplant to prove to yourself you’re not a total walking disaster of a person.
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Our Verdict
Claude Sonnet 4.5
Claude Sonnet 4.5
Seed 2.1 Turbo
Seed 2.1 Turbo

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

Seed 2.1 Turbo costs 6.0x less per token.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Claude Sonnet 4.5
Input
$3.00
Output
$15.00
Seed 2.1 Turbo
Input
$0.50
6.0× cheaper
Output
$2.50
6.0× cheaper

Seed 2.1 Turbo is cheaper on both: 6.0× input, 6.0× output.

Where to run it

5 hosts

Claude Sonnet 4.54 hosts
HostInOutContextUptime
Amazon Bedrock$3.00 in·$15.00 out·1M·99.9% upAzure AI Foundry$3.00 in·$15.00 out·200k·99.7% upAnthropic$3.00 in·$15.00 out·1M·100% upGoogle Vertex AI$3.00 in·$15.00 out·1M·99.8% up
Seed 2.1 Turbo1 host
HostInOutContextUptime
ByteDance Seedfp8$0.50 in·$2.50 out·262k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 16 Sep 2026.

Writing DNA

Style Comparison

Similarity
44%

Claude Sonnet 4.5 uses 6.8x more emoji

Claude Sonnet 4.5
Seed 2.1 Turbo
64%Vocabulary50%
94wSentence Length27w
0.48Hedging0.27
4.9Bold1.5
8.0Lists2.4
0.45Emoji0.07
1.91Headings1.01
0.07Transitions0.04
Based on 20 + 27 text responses
Research

What we learned reading every model

FAQ

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Model pages

Claude Sonnet 4.5 logo
Claude Sonnet 4.543 outputs, specs and price
Seed 2.1 Turbo logo
Seed 2.1 Turbo58 outputs, specs and price
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