Updated Sep 29, 2025

Our Verdict

Claude Sonnet 4.5

Claude 3 HaikuRunner-up

No community votes yet. On paper, Claude Sonnet 4.5 has the edge — bigger model tier, newer.

Claude 3 Haiku is 12x cheaper per token — worth considering if cost matters.

Too close to call

Writing DNA

Style Comparison

Similarity

99%

Claude Sonnet 4.5 uses 45.2x more emoji

Claude 3 Haiku

Claude Sonnet 4.5

50%Vocabulary64%

22wSentence Length94w

0.71Hedging0.48

0.3Bold4.9

5.9Lists8.0

0.00Emoji0.45

0.00Headings1.91

0.08Transitions0.07

Based on 13 + 20 text responses

vs

Ask them anything yourself

Claude 3 Haiku

Claude Sonnet 4.5

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026

Free preview13 of 58 slides

Download the free preview or get all 58 slides for $49

FAQ

Common questions

Keep going

Claude 3 Haiku vs GPT-5New provider

Claude 3 Haiku vs MiniMax M2.5New provider

Claude 3 Haiku vs Aurora AlphaNew provider

Claude 3 HaikuvsClaude Sonnet 4.5

37 fights queued

Why Claude 3 Haiku?

12x cheaper overall$0.25/M in · $1.25/M out

Why Claude Sonnet 4.5?

19 months newerSep 2025

Claude 3 HaikuClaude Sonnet 4.5

Input price

$0.25/M

$3.00/M

Output price

$1.25/M

$15.00/M

Context

200K

200K

Released

Mar 2024

Sep 2025

Favorites

Claude 3 HaikuClaude Sonnet 4.5

Movie

Spirited Away

Spirited Away

2001: A Space Odyssey

2001: A Space Odyssey

Album

Abbey Road

Kind of Blue

Book

Siddhartha

Siddhartha

Metamorphosis

Metamorphosis

City

Paris

Amsterdam

Game

Tetris (1984)

Tetris (1984)

Portal 2

Portal 2

Shooter, Puzzle4.6

12 / 37

01

Estimate Complexityreasoning

Tests an AI's ability to make educated estimates based on technical knowledge

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025text

I'll work through this estimation step by step, using what I know about GPT-3's architecture and training.

Known/Estimated Parameters

Model size:

GPT-3 (175B version) has ~175 billion parameters

Training data:

Trained on ~300 billion tokens (this was mentioned in the paper)

Architecture:

Transformer decoder-only model

FLOPs Calculation

For transformer models, there's an approximate rule for FLOPs per token:

FLOPs per token ≈ 6P (for forward pass) + 6P (for backward pass) = 12P total

Where P = number of parameters

This factor of 6 comes from:

2 FLOPs per multiply-accumulate operation
Each parameter is involved in approximately 3 operations per forward pass (attention, FFN layers, etc.)

Calculation:

Parameters (P): 175 × 10⁹
Tokens (T): 300 × 10⁹
FLOPs per token: 12P = 12 × 175 × 10⁹ = 2.1 × 10¹²

Total training FLOPs:

Total = FLOPs per token × number of tokens
Total = 2.1 × 10¹² × 300 × 10⁹
Total = 6.3 × 10²³ FLOPs

Final Estimate

~3-6 × 10²³ FLOPs (or ~300-600 zettaFLOPs)

This is roughly equivalent to running a GPU capable of 100 TFLOPS continuously for about 75,000 years, or more practically, running thousands of GPUs for several weeks.

Try this prompt

Vote

2 / 37

02

AI Board Game Logicreasoning

Tests an AI's ability to understand game rules and strategy

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

3 / 37

03

Logic Puzzlereasoning

Tests an AI's ability to solve a simple but potentially confusing logic puzzle

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

4 / 37

04

Stochastic Consistency Testanalysis

Tests an AI's randomness and creativity

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

5 / 37

05

SVG Layout Challengeimage generation

Tests an AI's ability to generate vector graphics

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

6 / 37

06

Xbox Controller SVG Artimage generation

Tests an AI's ability to create detailed SVG illustrations of gaming hardware

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

Sponsored

7 / 37

07

Generate a Stand-Up Routineconversation

Tests an AI's humor and creative writing ability

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

8 / 37

08

Character Voice Testconversation

Tests an AI's ability to write in distinct character voices

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

9 / 37

09

Pokémon Battle UI Recreationweb design

Recreate an interactive, nostalgic Pokémon battle UI in a single HTML file.

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024website

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025website

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

10 / 37

10

Mario Level UI Recreationweb design

Recreate an interactive, classic Mario level in a single HTML file.

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024website

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025website

Try this prompt

Vote

11 / 37

11

Linear App Cloneweb design

Tests an AI's ability to replicate an existing UI with Tailwind CSS

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024website

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025website

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

12 / 37

12

Framer-Style Animationweb design

Tests an AI's ability to create smooth web animations

Claude 3 Haiku

Claude 3 Haiku

Anthropic · Mar 2024website

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Claude Sonnet 4.5

Claude Sonnet 4.5

Anthropic · Sep 2025website

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

This matchup has more rounds

25+ more head-to-head results. Free. Not a trick.

Free account. No card required. By continuing, you agree to Rival's Terms and Privacy Policy