Life & fun · alternatives · 2026

24 alternatives to CTF Challenge Generator Suite

Build jeopardy-style CTF challenges in your browser

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.

1AC
A CTF challenge that let's you attack an LLM-based agent▲5
Hello HN, given the recent interest in the security vulnerabilities of agentic LLM apps, we would love to hear everyone's thoughts on a Capture The Flag (CTF) challenge we built. The challenge is designed to test the robustness of LLM-based agent systems, showcasing how an attacker can extract sensitive information from the system. The challenge is part of the Invariant Summer '24 CTF series, where participants can play the challenge and compete for a prize pool of $1000. Let us know what you think and what attacks you tried. We are also open to any feedback on how we can improve with the…
2024 · its alternatives →
2
CTFGuide▲79
CTFGuide provides tools to teach and learn cybersecurity
2021 · ctfguide.com · its alternatives →
3
Cracking passwords with a simple genetic algorithm▲149
Population based metaheuristic for password cracking. Siga(Simple genetic algorithm) - lyle-nel/siga
2016 · github.com · its alternatives →
4
I built a puzzle / programming challenge with a 0.125 BTC prize▲48
Fill out and generate PDFs with a simple API request. Design templates in our drag-and-drop editor, POST your JSON data, and download a finished PDF in seconds.
2018 · formapi.io · its alternatives →
5HC
Hackchain – Continuous Bitcoin-Inspired CTF Competition▲83
2016 · hackcha.in · its alternatives →
6
stegbrue▲3
Fast Steganography bruteforce tool useful for CTF's
2020 · github.com · its alternatives →
7SD
Secure Diceware Password Generator with zxcvbn entropy estimates▲10
Generate secure Diceware passphrases in 22 languages using your browser
2015 · grempe.github.io · its alternatives →
8
Password Generator▲87
An open-source cross-browser extension
2023 · github.com · its alternatives →
9
playCTF▲6
A Jeopardy style CTF creation and management platform
2022 · its alternatives →
10
onPASSWORD One▲65
An offline, open-source and memorable password generator
2022 · its alternatives →
11BS
Backdoor – Security CTF Platform▲12
2015 · backdoor.sdslabs.co · its alternatives →
12AM
A minimal TS library that generates prompt injection attacks▲33
I made an open source, MIT license Typescript library based on some of the latest research that generates prompt injection attacks. It is a super minimal/lightweight and designed to be super easy to use. Keen to hear your thoughts and please be responsible and only pen test systems where you have permission to pen test!
2025 · prompt-injector.blueprintlab.io · its alternatives →
13
Neerajlovecyber▲8
Cybersecurity insights, tools, and CTF resources
2025 · neerajlovecyber.com · its alternatives →
14
Simulations Labs▲25
Easiest Platform to Launch Cybersecurity Simulations
Dec 2025 · simulationslabs.com · its alternatives →
15
CSEM CTF▲11
Cyber Security Learning Make Easy
2025 · csem.sturtles.in · its alternatives →
16
ByteCTF▲6
A Begginer Friendly CTF Platform For Hackers
2025 · bytectf.netlify.app · its alternatives →
17
Smart City Defender▲12
Cyber Attack Response Game
2025 · ctf-smartcitydefense.netlify.app · its alternatives →
18
SQL Injection Challenge▲34
Pen test your "friend's" online MMORPG game - specific focus, sql injection opportunities - breakthenet/HackMe-SQL-Injection-Challenges
2016 · github.com · its alternatives →
19FL
Flaws: learn about common mistakes and gotchas when using AWS▲35
Learn AWS security with the flAWS challenge
2018 · flaws.cloud · its alternatives →
20
Free random code generator by codito.io▲9
I built a free online tool for generating large batches of unique random codes - up to 250,000 per generation (roughly 2.5M/hour). It's designed for cases like: - custom discount/voucher codes - giveaway or lottery tickets - product serial numbers printed on packaging - one-time passwords or secure tokens - bulk fake/test data - random strings You control: - quantity (up to 250k per batch) - length (up to 40 chars + optional prefix/suffix) - exact character sets (letters, digits, symbols, Unicode/emojis) - precise position rules (e.g. letters in positions 1-3, digits…
Jan 2026 · codito.io · its alternatives →
21
Custom Secret SeedPhrase Generator 12-24▲12
The First And Only Customizable Crypto Wallet Generator
2025 · cryptovurny.com · its alternatives →
22
Cracken – A Data Driven Approach for Password Generation▲10
a fast password wordlist generator, Smartlist creation and password hybrid-mask analysis tool written in pure safe Rust - shmuelamar/cracken
2021 · github.com · its alternatives →
23
Bitcoin Challenge. Try to steal a plain text private key you can use▲14
Hi HN, I'm releasing my round one public demo of a new browser security system I've been developing. There's a real Bitcoin private key (worth $20) in plaintext at app.redactsure.com. You can copy it, paste it, delete it, move it around - full control. But you can't see the actual characters or extract them. The challenge: Break the protection and take the Bitcoin. First person wins, challenge ends. Details: - Requires email verification (prevents abuse, no account needed) - 15 minute time limit per session - Currently US only for the demo (latency) - Verify the Bitcoin is real:…
2025 · app.redactsure.com · its alternatives →
24
Declaw Arena – a CTF-style challenge to break an AI agent in a microVM▲8
An interactive security challenge. Control an AI agent and try to exfiltrate data from a sandboxed environment protected by Declaw.
Jul 2026 · declaw.ai · its alternatives →

Also compare

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →