CTF servers

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

Server	Members	Online	Active
1 HackTheBoxverified	386,605	28,060	7.3%
2 TryHackMeverified	373,684	24,264	6.5%
3 OwlSecpartner	174,310	12,066	6.9%
4 JH Discord	30,265	2,986	9.9%
5 Root-Me	28,505	2,803	9.8%
6 OverTheWire	27,695	2,297	8.3%
7 SANS Holiday Hack Challenge	18,765	1,651	8.8%
8 ImaginaryCTF	14,115	1,549	11.0%
9 CTFlearn	11,987	725	6.0%
10 Hack This Fall Community	11,717	130	1.1%
11 CryptoHack	10,747	1,310	12.2%
12 crackmes.one	6,964	1,124	16.1%
13 SECCON Beginners CTF	6,723	807	12.0%
14 SkillBit (formerly MetaCTF)	6,176	907	14.7%
15 FCSC & Hackropole	6,060	800	13.2%
16 GoogleCTF	5,449	849	15.6%
17 HITCON CTF	5,389	1,078	20.0%
18 SekaiCTF 2026	5,147	822	16.0%
19 TCP1P Server	4,907	576	11.7%
20 Cyber Security Challenge Germany	4,262	540	12.7%
21 ångstromCTF	3,934	366	9.3%
22 VishwaCTF	3,919	103	2.6%
23 Real World CTF	3,715	272	7.3%
24 UIUCTF 2026	3,669	520	14.2%
25 Hack United	3,609	208	5.8%
26 SunshineCTF	3,594	337	9.4%
27 Midnight Sun CTF	3,574	620	17.3%
28 nullcon HackIM 2026	3,455	166	4.8%
29 ASIS CTF	3,419	329	9.6%
30 UTCTF 2026	3,373	377	11.2%
31 PatriotCTF 2026	3,339	512	15.3%
32 scriptCTF	3,232	232	7.2%
33 HeroCTF	3,192	234	7.3%
34 idekCTF	3,178	352	11.1%
35 247CTF	3,141	193	6.1%
36 NorthSec	3,127	729	23.3%
37 b01lersCTF	3,086	329	10.7%
38 UMassCTF 2026	3,025	314	10.4%
39 BuckeyeCTF 2025	2,899	510	17.6%
40 DEADFACE CTF	2,851	320	11.2%
41 corCTF	2,712	309	11.4%
42 KalmarCTF	2,706	543	20.1%
43 Hacking-Lab	2,699	110	4.1%
44 Kaspersky{CTF}	2,687	177	6.6%
45 Official HackMyVM	2,648	111	4.2%
46 HSCTF	2,616	206	7.9%
47 CrewCTF 2025	2,584	282	10.9%
48 KnightCTF	2,564	157	6.1%
49 TSG CTF	2,522	194	7.7%
50 Hack.lu CTF	2,478	357	14.4%
51 smileyCTF 2025	2,473	250	10.1%
52 XCTF 10th–SCTF 2026	2,428	102	4.2%
53 niteCTF '25	2,407	146	6.1%
54 GPN CTF 2026	2,400	267	11.1%
55 rCTF	2,381	170	7.1%
56 Midnight Flag CTF - EXECUTION	2,327	216	9.3%
57 DIVER OSINT CTF	2,318	326	14.1%
58 HACKTORIA	2,235	171	7.7%
59 R3CTF 2026	2,170	278	12.8%
60 NNS CTF	2,100	196	9.3%
61 b01lers	2,081	576	27.7%
62 1753CTF	2,079	172	8.3%
63 HackTheBox_KE	2,038	28	1.4%
64 Dev Universe - FGTE CTF	1,921	164	8.5%
65 UMDCTF 2026	1,914	272	14.2%
66 HackDay	1,903	251	13.2%
67 PrimeSec	1,890	121	6.4%
68 SECCON CTF 14	1,882	272	14.5%
69 BCACTF	1,853	167	9.0%
70 CTF@CIT	1,845	183	9.9%
71 JerseyCTF 🔒	1,835	248	13.5%
72 eCitadel	1,796	624	34.7%
73 Cyber Odyssey: Akasec CTF	1,784	161	9.0%
74 InCTF Nationals	1,777	32	1.8%
75 zer0pts CTF	1,758	197	11.2%
76 jailCTF 2026	1,750	177	10.1%
77 N0PSctf	1,726	142	8.2%
78 SECCON CTF 13	1,711	226	13.2%
79 IrisCTF	1,675	189	11.3%
80 BlahajCTF	1,634	179	11.0%
81 PSU CCSO	1,612	198	12.3%
82 HAXAGON Community	1,521	139	9.1%
83 pwnable.tw	1,507	165	10.9%
84 DamCTF	1,505	166	11.0%
85 xCTFs	1,470	276	18.8%
86 TetCTF	1,421	125	8.8%
87 CyberDawgs Club	1,411	101	7.2%
88 ZeroDays CTF	1,409	67	4.8%
89 ECW CTF	1,392	194	13.9%
90 TAMUctf 2026	1,392	187	13.4%
91 RITSEC CTF	1,374	219	15.9%
92 SECCON CTF 2023	1,351	154	11.4%
93 FAUST CTF 2026	1,338	172	12.9%
94 Reply CTF Challenge	1,335	58	4.3%
95 Sieberrsec CTF	1,296	76	5.9%
96 @Hack CTF - Concordia	1,294	83	6.4%
97 CyberSpace CTF 2024	1,274	118	9.3%
98 CakeCTF 2023	1,260	116	9.2%
99 MontréHack	1,259	241	19.1%
100 hackerspace - DropCTF	1,243	127	10.2%
101 ISITDTU-CTF	1,240	69	5.6%
102 Hack In The North	1,240	10	0.8%
103 AlpacaHack	1,232	207	16.8%
104 SWIMMER OSINT CTF	1,228	143	11.6%
105 UnitedCTF	1,215	279	23.0%
106 WaniCTF	1,209	157	13.0%
107 SpookyCTF	1,151	133	11.6%
108 wpictf	1,145	46	4.0%
109 DaVinciCTF	1,139	101	8.9%
110 HKCERT CTF 2024	1,118	120	10.7%
111 RingZer0 CTF	1,114	130	11.7%
112 Shutlock CTF 🕵	1,104	94	8.5%
113 pingCTF 2026	1,103	81	7.3%
114 NCKUCTF	1,097	282	25.7%
115 BDSec CTF	1,080	66	6.1%
116 Swiss Hacking Challenge	1,058	84	7.9%
117 Paradigm CTF	1,047	108	10.3%
118 ZishanHack	1,039	38	3.7%
119 x3CTF 2026	1,027	151	14.7%
120 squ1rrel CTF 2026	1,027	134	13.0%
121 RACTF	1,017	76	7.5%
122 Olympics CTF	995	51	5.1%
123 PearlCTF	988	58	5.9%
124 IRON CTF 2024	978	78	8.0%
125 Pragyan CTF'26	978	76	7.8%
126 BERKE1337	956	119	12.4%
127 pwnable.kr	952	96	10.1%
128 SwampCTF	942	93	9.9%
129 Arab & Africa Regional CTF	935	24	2.6%
130 Break the Syntax CTF	934	109	11.7%
131 Swinburne Cyber Security Club (SCSC)	914	131	14.3%
132 World Wide Hack	907	77	8.5%
133 P3rf3ctr00t CTF	897	51	5.7%
134 offsec	886	54	6.1%
135 Wargames.MY CTF 2024	884	69	7.8%
136 BRICS+ CTF	883	66	7.5%
137 pwntools	883	111	12.6%
138 CyberSecurityRumble	877	105	12.0%
139 NewbieContest	873	63	7.2%
140 Otaku hunters	844	58	6.9%
141 RPISEC	831	109	13.1%
142 Wizer CTF	803	36	4.5%
143 DAMSEC CTF LEAGUE	796	128	16.1%
144 Cryptocracy™	790	17	2.2%
145 EnigmaXplore 3.0	771	34	4.4%
146 snakeCTF	766	95	12.4%
147 HACK'OSINT - CTF	759	98	12.9%
148 Hack-A-Sat	742	111	15.0%
149 HackTheMidlands	740	36	4.9%
150 07CTF	734	84	11.4%