CTF servers

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

Server	Members	Online	Active
1 HackTheBoxverified	388,876	28,609	7.4%
2 TryHackMeverified	375,862	24,822	6.6%
3 OwlSecpartner	172,128	13,205	7.7%
4 JH Discord	30,301	2,884	9.5%
5 Root-Me	28,427	2,671	9.4%
6 OverTheWire	27,890	2,449	8.8%
7 SANS Holiday Hack Challenge	19,177	1,607	8.4%
8 ImaginaryCTF	14,158	1,339	9.5%
9 CTFlearn	12,078	642	5.3%
10 Hack This Fall Community	11,759	83	0.7%
11 CryptoHack	10,815	1,202	11.1%
12 crackmes.one	6,864	1,232	17.9%
13 SECCON Beginners CTF	6,735	760	11.3%
14 FCSC & Hackropole	6,088	1,149	18.9%
15 SkillBit (formerly MetaCTF)	6,068	832	13.7%
16 GoogleCTF	5,506	1,040	18.9%
17 SekaiCTF 2026	5,201	711	13.7%
18 TCP1P Server	4,824	367	7.6%
19 Cyber Security Challenge Germany	4,284	184	4.3%
20 HITCON CTF	4,273	681	15.9%
21 ångstromCTF	3,982	331	8.3%
22 VishwaCTF	3,952	83	2.1%
23 Real World CTF	3,734	232	6.2%
24 UIUCTF 2026	3,714	516	13.9%
25 SunshineCTF	3,684	339	9.2%
26 Midnight Sun CTF	3,600	699	19.4%
27 Hack United	3,569	205	5.7%
28 nullcon HackIM 2026	3,479	149	4.3%
29 ASIS CTF	3,438	278	8.1%
30 UTCTF 2026	3,404	325	9.5%
31 PatriotCTF 2026	3,354	622	18.5%
32 scriptCTF	3,258	219	6.7%
33 HeroCTF	3,216	212	6.6%
34 idekCTF	3,198	303	9.5%
35 247CTF	3,188	227	7.1%
36 NorthSec	3,143	698	22.2%
37 b01lersCTF	3,111	302	9.7%
38 UMassCTF 2026	3,051	252	8.3%
39 BuckeyeCTF 2025	2,919	516	17.7%
40 corCTF	2,729	504	18.5%
41 KalmarCTF	2,726	692	25.4%
42 Hacking-Lab	2,725	251	9.2%
43 Kaspersky{CTF}	2,718	236	8.7%
44 HSCTF	2,637	181	6.9%
45 Official HackMyVM	2,631	115	4.4%
46 CrewCTF 2025	2,596	213	8.2%
47 KnightCTF	2,580	136	5.3%
48 TSG CTF	2,545	201	7.9%
49 smileyCTF 2025	2,501	315	12.6%
50 XCTF 10th–SCTF 2026	2,442	102	4.2%
51 GPN CTF 2026	2,432	182	7.5%
52 niteCTF '25	2,424	128	5.3%
53 rCTF	2,420	193	8.0%
54 Midnight Flag CTF - EXECUTION	2,342	204	8.7%
55 DIVER OSINT CTF	2,328	309	13.3%
56 HACKTORIA	2,189	249	11.4%
57 R3CTF 2026	2,185	298	13.6%
58 DEADFACE CTF	2,177	319	14.7%
59 NNS CTF	2,146	387	18.0%
60 CCDC	2,095	730	34.8%
61 1753CTF	2,094	143	6.8%
62 UMDCTF 2026	2,094	250	11.9%
63 b01lers	2,078	295	14.2%
64 HackTheBox_KE	2,029	22	1.1%
65 Hack.lu CTF	1,990	181	9.1%
66 Dev Universe - FGTE CTF	1,920	119	6.2%
67 JerseyCTF 🔒	1,909	244	12.8%
68 HackDay	1,909	96	5.0%
69 SECCON CTF 14	1,890	281	14.9%
70 BCACTF	1,871	152	8.1%
71 CTF@CIT	1,858	154	8.3%
72 eCitadel	1,802	581	32.2%
73 Cyber Odyssey: Akasec CTF	1,788	73	4.1%
74 InCTF Nationals	1,772	24	1.4%
75 zer0pts CTF	1,771	174	9.8%
76 jailCTF 2026	1,763	152	8.6%
77 N0PSctf	1,734	149	8.6%
78 SECCON CTF 13	1,718	206	12.0%
79 IrisCTF	1,694	154	9.1%
80 PSU CCSO	1,617	199	12.3%
81 BlahajCTF	1,601	127	7.9%
82 DamCTF	1,522	145	9.5%
83 HAXAGON Community	1,514	46	3.0%
84 pwnable.tw	1,513	121	8.0%
85 ZeroDays CTF	1,456	58	4.0%
86 xCTFs	1,438	251	17.5%
87 TetCTF	1,427	124	8.7%
88 ECW CTF	1,423	92	6.5%
89 CyberDawgs Club	1,415	206	14.6%
90 TAMUctf 2026	1,397	179	12.8%
91 RITSEC CTF	1,384	252	18.2%
92 Reply CTF Challenge	1,382	53	3.8%
93 SECCON CTF 2023	1,359	144	10.6%
94 FAUST CTF 2026	1,353	149	11.0%
95 Sieberrsec CTF	1,298	106	8.2%
96 @Hack CTF - Concordia	1,293	160	12.4%
97 CyberSpace CTF 2024	1,287	118	9.2%
98 CakeCTF 2023	1,277	151	11.8%
99 hackerspace - DropCTF	1,277	113	8.8%
100 ISITDTU-CTF	1,254	112	8.9%
101 MontréHack	1,253	208	16.6%
102 Hack In The North	1,242	13	1.0%
103 SWIMMER OSINT CTF	1,234	166	13.5%
104 AlpacaHack	1,226	180	14.7%
105 WaniCTF	1,219	139	11.4%
106 UnitedCTF	1,219	281	23.1%
107 wpictf	1,184	42	3.5%
108 OmniCTF | Public	1,165	168	14.4%
109 DaVinciCTF	1,147	65	5.7%
110 HKCERT CTF 2024	1,119	92	8.2%
111 RingZer0 CTF	1,116	163	14.6%
112 Shutlock CTF 🕵	1,107	139	12.6%
113 pingCTF 2026	1,100	73	6.6%
114 NCKUCTF	1,093	170	15.6%
115 BDSec CTF	1,093	56	5.1%
116 Swiss Hacking Challenge	1,082	128	11.8%
117 RACTF	1,072	54	5.0%
118 Paradigm CTF	1,057	104	9.8%
119 ZishanHack	1,041	23	2.2%
120 HackTheMidlands	1,037	77	7.4%
121 squ1rrel CTF 2026	1,037	109	10.5%
122 x3CTF 2026	1,018	113	11.1%
123 Olympics CTF	1,004	51	5.1%
124 PearlCTF	992	74	7.5%
125 Pragyan CTF'26	990	69	7.0%
126 IRON CTF 2024	990	62	6.3%
127 SpookyCTF	963	100	10.4%
128 SwampCTF	944	82	8.7%
129 BERKE1337	942	127	13.5%
130 Arab & Africa Regional CTF	938	36	3.8%
131 Break the Syntax CTF	938	69	7.4%
132 pwnable.kr	923	92	10.0%
133 Swinburne Cyber Security Club (SCSC)	918	89	9.7%
134 World Wide Hack	910	63	6.9%
135 offsec	908	54	5.9%
136 P3rf3ctr00t CTF	900	31	3.4%
137 BRICS+ CTF	890	51	5.7%
138 pwntools	887	86	9.7%
139 Wargames.MY CTF 2024	887	45	5.1%
140 NewbieContest	885	80	9.0%
141 CyberSecurityRumble	884	78	8.8%
142 Otaku hunters	844	64	7.6%
143 RPISEC	834	203	24.3%
144 Wizer CTF	812	52	6.4%
145 DAMSEC CTF LEAGUE	797	125	15.7%
146 Cryptocracy™	795	16	2.0%
147 snakeCTF	774	130	16.8%
148 EnigmaXplore 3.0	774	31	4.0%
149 HACK'OSINT - CTF	762	52	6.8%
150 Hack-A-Sat	748	108	14.4%