Life & fun · alternatives · 2026
24 alternatives to Backdoor – Security CTF Platform
Backdoor is a security capture-the-flag platform where users solve cybersecurity challenges and puzzles. Designed for people interested in learning and practicing information security skills, it offers a competitive… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Backdoor – Security CTF Platform launched in 2015; newer entries below may have overtaken it.
- 1
A totally proof-of-concept FoundationDB based network block device backend - dividuum/fdb-nbd
2018 · github.com · its alternatives →
- 2HC
2016 · hackcha.in · its alternatives →
- 3
2021 · github.com · its alternatives →
- 4
🛡️ Open-source and cloud-native Web Application Firewall (WAF) - bunkerity/bunkerweb
2024 · github.com · its alternatives →
- 5HA
2014 · hacker.surf · its alternatives →
- 6
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- 9
Documentation of BunkerWeb, the open source and next generation WAF.
2025 · docs.bunkerweb.io · its alternatives →
- 10
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- 12HOHackerhub.org▲101
2011 · hackerhub.org · its alternatives →
- 13
- 14
- 15CH
2016 · code.hackmit.org · its alternatives →
- 16HI
2015 · hackjobio.herokuapp.com · its alternatives →
- 17
A free, fun platform to learn about cryptography through solving challenges and cracking insecure code. Can you reach the top of the leaderboard?
2020 · cryptohack.org · its alternatives →
- 18
CTFGuide▲79CTFGuide provides tools to teach and learn cybersecurity
2021 · ctfguide.com · its alternatives →
- 19
SecHub▲12SecHub - an educational platform to learn about web-security
2019 · sechub.io · its alternatives →
- 20
- 21
HackenProof▲74A crowd-sourced cyber security testing platform
2019 · hackenproof.com · its alternatives →
- 22
Companies need ethical hackers more than ever
2022 · hckrt.com · its alternatives →
- 23
We build runtime security for AI agents. The playground started as an internal tool that we used to test our own guardrails. But we kept finding the same types of vulnerabilities because we think about attacks a certain way. At some point you need people who don't think like you. So we open-sourced it. Each challenge is a live agent with real tools and a published system prompt. Whenever a challenge is over, the full winning conversation transcript and guardrail logs get documented publicly. Building the general-purpose agent itself was probably the most fun part. Getting it to reliably use…
Mar 2026 · github.com · its alternatives →
- 24FL
Learn AWS security with the flAWS challenge
2018 · flaws.cloud · its alternatives →
Also compare
- A proof-of-concept FoundationDB based network block device backend alternatives
- Hackchain – Continuous Bitcoin-Inspired CTF Competition alternatives
- Endgame – An AWS Pentesting tool to backdoor or expose AWS resources alternatives
- BunkerWeb – The Open-Source Web Application Firewall (WAF) alternatives
- HackerSurf – All the hacker jobs in one place alternatives
- CryptoHack alternatives
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 →