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

/26

No solved challenges yet.

Today's Challenge

Submissions (latest 3)

itsuki-t

SOLVED!

Jun 25, 8:26 PM

pppp4649

SOLVED!

Jun 25, 7:44 PM

kurgm

SOLVED!

Jun 25, 5:32 PM

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🌱

244 solves

minaminao

Cache Me If You Can

Web

Easy🌱

204 solves

minaminao

vm1

Misc

Medium

98 solves

pppp4649

Small e

Crypto

Easy🌱

137 solves

minaminao

RPS GAME

Misc

Crypto

Medium

99 solves

nozokare

Flag for localhost

Web

Easy🌱

171 solves

tan90909090

C++ flag checker

Rev

Hard

86 solves

shiragi

Guess IP

Misc

Easy🌱

143 solves

nozokare

A Piece of DHKE

Crypto

Medium

82 solves

shiragi

chmod-swapper

Misc

Medium

85 solves

tchen

Alpaca Certification

Web

Easy🌱

159 solves

rsk0315

Floating Equality

Misc

Medium

90 solves

pppp4649

Elliptic Equation

Crypto

Hard

59 solves

tchen

CAuth

Web

Hard

65 solves

minaminao

SITE/2

Web

Easy🌱

118 solves

tan90909090

Xored PNG

Misc

Medium

87 solves

tchen

Looks like Alpacahack

Web

Medium

81 solves

shiragi

Catrunner 2

Misc

Easy🌱

105 solves

minaminao

Flag Printer 20XX

Misc

Medium

63 solves

nozokare

xorshift521

Crypto

Hard

54 solves

k0080

what-is-my-size

Pwn

Hard

63 solves

minaminao

✌️✌️✌️

Crypto

Easy🌱

88 solves

tchen

Secret Renderer

Web

Medium

79 solves

kanon

honk the klaxon

Crypto

Medium

53 solves

colza

voyage

Misc

Easy🌱

84 solves

rsk0315

Decimal float 101.0

Misc

Medium

17 solves

bubu

Planned topicClient-Side

Web

Hard

pppp4649

Planned topicTBA

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 06/25/voyage/colza

tsukuyomi-chan

voyage

5 hours ago

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

Writeup for ✌️✌️✌️

baumroll1234

✌️✌️✌️

2026/06/22 18:13

Writeup for ✌️✌️✌️

minaminao

author

✌️✌️✌️

2026/06/22 17:14

Daily AlpacaHackに挑戦するつくよみちゃん 06/22/✌️✌️✌️/minaminao

tsukuyomi-chan

✌️✌️✌️

2026/06/22 16:47

Writeup for ✌️✌️✌️

tadanobutubutu

✌️✌️✌️

2026/06/22 15:53

Writeup for what-is-my-size

tadanobutubutu

what-is-my-size

2026/06/22 13:57

Writeup for what-is-my-size

goroshirow

what-is-my-size

2026/06/21 16:19

Rows:

CAuth

Topic: JSONReleased: Jun 14, 2026

65 solves

Web

Hard6.0

tchen

USER	SOLVED AT
stepbystepbymyself	2026/06/21 13:14
n0ir	2026/06/21 09:23
bassamassiri	2026/06/21 02:03
sensei123	2026/06/20 18:18
aiueo6614	2026/06/16 07:44
gattoartz	2026/06/15 09:49
mg7x	2026/06/14 23:05
labpump	2026/06/14 14:50
tomatonosenpai	2026/06/14 14:47
tenagazaru	2026/06/14 14:40
bono	2026/06/14 14:06
nitcelcius	2026/06/14 12:53
tyage	2026/06/14 12:18
ahnmo	2026/06/14 12:08
xnmhuveb	2026/06/14 11:41
mizore-fuyu	2026/06/14 11:12
karanokuri	2026/06/14 10:40
tadanobutubutu	2026/06/14 10:16
nomeaning	2026/06/14 10:11
goroshirow	2026/06/14 09:36
iori	2026/06/14 08:41
kinner	2026/06/14 08:16
bn256	2026/06/14 08:12
n0name	2026/06/14 07:54
shiragi	2026/06/14 07:46