CTF servers

150 measured server(s) with the CTF sub-topic, ranked by real members. Browse topics →

Server	Members	Online	Active
1 HackTheBoxverified	389,456	25,323	6.5%
2 TryHackMeverified	376,386	21,433	5.7%
3 OwlSecpartner	172,683	11,967	6.9%
4 JH Discord	30,368	2,718	9.0%
5 Root-Me	28,467	1,802	6.3%
6 OverTheWire	27,919	2,021	7.2%
7 SANS Holiday Hack Challenge	19,161	1,398	7.3%
8 ImaginaryCTF	14,150	1,423	10.1%
9 CTFlearn	12,078	652	5.4%
10 Hack This Fall Community	11,753	141	1.2%
11 CryptoHack	10,819	1,251	11.6%
12 crackmes.one	6,891	1,061	15.4%
13 SECCON Beginners CTF	6,733	825	12.3%
14 FCSC & Hackropole	6,080	1,342	22.1%
15 SkillBit (formerly MetaCTF)	6,063	860	14.2%
16 GoogleCTF	5,499	1,033	18.8%
17 SekaiCTF 2026	5,186	811	15.6%
18 TCP1P Server	4,844	567	11.7%
19 HITCON CTF	4,567	861	18.9%
20 Cyber Security Challenge Germany	4,280	225	5.3%
21 ångstromCTF	3,978	348	8.7%
22 VishwaCTF	3,942	99	2.5%
23 Real World CTF	3,734	277	7.4%
24 UIUCTF 2026	3,698	641	17.3%
25 SunshineCTF	3,664	556	15.2%
26 Midnight Sun CTF	3,590	585	16.3%
27 Hack United	3,582	192	5.4%
28 nullcon HackIM 2026	3,476	185	5.3%
29 ASIS CTF	3,438	324	9.4%
30 UTCTF 2026	3,398	360	10.6%
31 PatriotCTF 2026	3,349	645	19.3%
32 scriptCTF	3,252	248	7.6%
33 HeroCTF	3,208	224	7.0%
34 idekCTF	3,191	346	10.8%
35 247CTF	3,180	179	5.6%
36 NorthSec	3,137	687	21.9%
37 b01lersCTF	3,107	316	10.2%
38 UMassCTF 2026	3,041	318	10.5%
39 DEADFACE CTF	2,948	554	18.8%
40 BuckeyeCTF 2025	2,914	356	12.2%
41 corCTF	2,726	514	18.9%
42 KalmarCTF	2,721	680	25.0%
43 Hacking-Lab	2,718	111	4.1%
44 Kaspersky{CTF}	2,707	178	6.6%
45 Official HackMyVM	2,637	109	4.1%
46 HSCTF	2,636	184	7.0%
47 CrewCTF 2025	2,591	254	9.8%
48 KnightCTF	2,571	155	6.0%
49 TSG CTF	2,541	227	8.9%
50 smileyCTF 2025	2,492	244	9.8%
51 XCTF 10th–SCTF 2026	2,441	117	4.8%
52 GPN CTF 2026	2,422	264	10.9%
53 niteCTF '25	2,419	132	5.5%
54 rCTF	2,419	183	7.6%
55 Midnight Flag CTF - EXECUTION	2,336	218	9.3%
56 DIVER OSINT CTF	2,325	314	13.5%
57 HACKTORIA	2,214	163	7.4%
58 R3CTF 2026	2,183	233	10.7%
59 NNS CTF	2,131	193	9.1%
60 CCDC	2,117	805	38.0%
61 Hack.lu CTF	2,091	237	11.3%
62 1753CTF	2,087	145	6.9%
63 b01lers	2,087	525	25.2%
64 UMDCTF 2026	2,055	260	12.7%
65 HackTheBox_KE	2,034	27	1.3%
66 Dev Universe - FGTE CTF	1,919	114	5.9%
67 HackDay	1,911	109	5.7%
68 SECCON CTF 14	1,887	290	15.4%
69 BCACTF	1,866	165	8.8%
70 JerseyCTF 🔒	1,865	222	11.9%
71 CTF@CIT	1,855	150	8.1%
72 PrimeSec	1,809	95	5.3%
73 eCitadel	1,799	634	35.2%
74 Cyber Odyssey: Akasec CTF	1,786	49	2.7%
75 InCTF Nationals	1,773	26	1.5%
76 zer0pts CTF	1,770	194	11.0%
77 jailCTF 2026	1,757	176	10.0%
78 N0PSctf	1,733	123	7.1%
79 SECCON CTF 13	1,716	229	13.3%
80 IrisCTF	1,687	184	10.9%
81 PSU CCSO	1,614	131	8.1%
82 BlahajCTF	1,613	144	8.9%
83 HAXAGON Community	1,520	68	4.5%
84 pwnable.tw	1,516	156	10.3%
85 DamCTF	1,515	144	9.5%
86 ZeroDays CTF	1,451	58	4.0%
87 xCTFs	1,447	254	17.6%
88 TetCTF	1,426	103	7.2%
89 ECW CTF	1,414	298	21.1%
90 CyberDawgs Club	1,413	218	15.4%
91 TAMUctf 2026	1,393	223	16.0%
92 RITSEC CTF	1,384	241	17.4%
93 Reply CTF Challenge	1,380	48	3.5%
94 SECCON CTF 2023	1,358	150	11.0%
95 FAUST CTF 2026	1,349	164	12.2%
96 Sieberrsec CTF	1,298	90	6.9%
97 @Hack CTF - Concordia	1,293	191	14.8%
98 CyberSpace CTF 2024	1,285	109	8.5%
99 hackerspace - DropCTF	1,273	131	10.3%
100 CakeCTF 2023	1,273	124	9.7%
101 ISITDTU-CTF	1,253	110	8.8%
102 MontréHack	1,252	231	18.5%
103 Hack In The North	1,242	13	1.0%
104 SWIMMER OSINT CTF	1,232	176	14.3%
105 AlpacaHack	1,229	213	17.3%
106 UnitedCTF	1,220	261	21.4%
107 WaniCTF	1,216	119	9.8%
108 wpictf	1,184	44	3.7%
109 OmniCTF | Public	1,162	134	11.5%
110 DaVinciCTF	1,147	89	7.8%
111 RingZer0 CTF	1,119	173	15.5%
112 HKCERT CTF 2024	1,119	110	9.8%
113 Shutlock CTF 🕵	1,104	78	7.1%
114 pingCTF 2026	1,099	89	8.1%
115 NCKUCTF	1,097	199	18.1%
116 BDSec CTF	1,088	89	8.2%
117 Swiss Hacking Challenge	1,079	104	9.6%
118 RACTF	1,072	63	5.9%
119 Paradigm CTF	1,053	105	10.0%
120 ZishanHack	1,043	35	3.4%
121 HackTheMidlands	1,035	83	8.0%
122 squ1rrel CTF 2026	1,032	141	13.7%
123 x3CTF 2026	1,025	118	11.5%
124 Olympics CTF	999	84	8.4%
125 PearlCTF	990	71	7.2%
126 Pragyan CTF'26	989	80	8.1%
127 IRON CTF 2024	987	94	9.5%
128 SpookyCTF	972	85	8.7%
129 SwampCTF	944	94	10.0%
130 BERKE1337	942	107	11.4%
131 Break the Syntax CTF	937	109	11.6%
132 Arab & Africa Regional CTF	935	21	2.2%
133 pwnable.kr	931	108	11.6%
134 Swinburne Cyber Security Club (SCSC)	919	128	13.9%
135 World Wide Hack	910	81	8.9%
136 offsec	908	56	6.2%
137 P3rf3ctr00t CTF	901	56	6.2%
138 pwntools	889	102	11.5%
139 BRICS+ CTF	887	69	7.8%
140 Wargames.MY CTF 2024	886	64	7.2%
141 CyberSecurityRumble	884	111	12.6%
142 NewbieContest	881	51	5.8%
143 Otaku hunters	845	54	6.4%
144 RPISEC	836	94	11.2%
145 Wizer CTF	809	28	3.5%
146 DAMSEC CTF LEAGUE	798	156	19.5%
147 Cryptocracy™	795	17	2.1%
148 EnigmaXplore 3.0	774	44	5.7%
149 snakeCTF	772	137	17.7%
150 HACK'OSINT - CTF	762	103	13.5%