Daily AlpacaHack

A daily CTF challenge with a fun new puzzle every day

What is Daily AlpacaHack?

We publish one simple, beginner-friendly or educational CTF challenge every day!

Join Anytime

Solve within 24 hours of release to appear on the leaderboard.

Not a Competition

Discussion with friends or AI is welcome (account sharing is prohibited).

Solution Sharing Rules

Sharing solutions is allowed only after 24 hours have passed since release.

Solve stats

/27

No solved challenges yet.

Today's Challenge

Submissions (latest 3)

nomeaning

SOLVED!

Jun 27, 12:52 PM

404gh0st

SOLVED!

Jun 27, 12:36 PM

hiroyuki

SOLVED!

Jun 27, 10:18 AM

Leaderboard

Period

Try the first challenge

Is this your first CTF? Let's begin by tackling the first challenge released on Daily AlpacaHack.

Upcoming challenges reveal the , , and in advance.

Jun 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

admin

Half-Year Recap

Misc

Welcome🌱

248 solves

minaminao

Cache Me If You Can

Web

Easy🌱

208 solves

minaminao

vm1

Misc

Medium

101 solves

pppp4649

Small e

Crypto

Easy🌱

140 solves

minaminao

RPS GAME

Misc

Crypto

Medium

99 solves

nozokare

Flag for localhost

Web

Easy🌱

176 solves

tan90909090

C++ flag checker

Rev

Hard

87 solves

shiragi

Guess IP

Misc

Easy🌱

144 solves

nozokare

A Piece of DHKE

Crypto

Medium

83 solves

shiragi

chmod-swapper

Misc

Medium

86 solves

tchen

Alpaca Certification

Web

Easy🌱

161 solves

rsk0315

Floating Equality

Misc

Medium

91 solves

pppp4649

Elliptic Equation

Crypto

Hard

60 solves

tchen

CAuth

Web

Hard

69 solves

minaminao

SITE/2

Web

Easy🌱

121 solves

tan90909090

Xored PNG

Misc

Medium

87 solves

tchen

Looks like Alpacahack

Web

Medium

83 solves

shiragi

Catrunner 2

Misc

Easy🌱

106 solves

minaminao

Flag Printer 20XX

Misc

Medium

63 solves

nozokare

xorshift521

Crypto

Hard

54 solves

k0080

what-is-my-size

Pwn

Hard

65 solves

minaminao

✌️✌️✌️

Crypto

Easy🌱

89 solves

tchen

Secret Renderer

Web

Medium

81 solves

kanon

honk the klaxon

Crypto

Medium

58 solves

colza

voyage

Misc

Easy🌱

90 solves

rsk0315

Decimal float 101.0

Misc

Medium

62 solves

bubu

Style Your Alpaca

Web

Hard

48 solves

pppp4649

Planned topicStack

Pwn

Hard

Coming soon

admin

Planned topicWelcome

Misc

Welcome🌱

hiikunz

Planned topicMathematics

Crypto

Easy🌱

Coming soon

hiikunz

Planned topicJavaScript

Rev

Medium

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Daily AlpacaHackに挑戦するつくよみちゃん 06/14/CAuth/tchen

tsukuyomi-chan

CAuth

42 minutes ago

Daily AlpacaHackに挑戦するつくよみちゃん 06/13/Elliptic Equation/pppp4649

tsukuyomi-chan

Elliptic Equation

2 hours ago

Daily AlpacaHackに挑戦するつくよみちゃん 06/12/Floating Equality/rsk0315

tsukuyomi-chan

Floating Equality

3 hours ago

Daily AlpacaHackに挑戦するつくよみちゃん 06/26/Decimal float 101.0/rsk0315

tsukuyomi-chan

Decimal float 101.0

17 hours ago

Writeup for Decimal float 101.0

nitcelcius

Decimal float 101.0

20 hours ago

Writeup for No JS

00xcanelo

No JS

2026/06/26 07:35

Daily AlpacaHackに挑戦するつくよみちゃん 06/25/voyage/colza

tsukuyomi-chan

voyage

2026/06/25 15:54

Writeup for honk the klaxon

baumroll1234

honk the klaxon

2026/06/24 20:02

Writeup for honk the klaxon

goroshirow

honk the klaxon

2026/06/24 15:33

Daily AlpacaHackに挑戦するつくよみちゃん 06/23/Secret Renderer/tchen

tsukuyomi-chan

Secret Renderer

2026/06/23 16:17

Rows:

simpleoverwrite

Topic: [Mirror] SECCON Beginners CTFReleased: Dec 27, 2025

220 solves

Pwn

n01e0