CTF servers

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

Server	Members	Online	Active
1 HackTheBoxverified	385,208	29,552	7.7%
2 TryHackMeverified	372,332	32,721	8.8%
3 OwlSecpartner	163,853	13,365	8.2%
4 JH Discord	30,151	3,086	10.2%
5 Root-Me	28,357	1,668	5.9%
6 OverTheWire	27,542	2,373	8.6%
7 SANS Holiday Hack Challenge	19,263	1,672	8.7%
8 ImaginaryCTF	14,165	1,704	12.0%
9 CTFlearn	12,105	649	5.4%
10 Hack This Fall Community	11,806	91	0.8%
11 CryptoHack	10,747	1,368	12.7%
12 SECCON Beginners CTF	6,750	936	13.9%
13 crackmes.one	6,672	1,255	18.8%
14 FCSC & Hackropole	6,118	1,125	18.4%
15 SkillBit (formerly MetaCTF)	5,963	732	12.3%
16 GoogleCTF	5,556	1,055	19.0%
17 SekaiCTF 2026	5,293	1,186	22.4%
18 TCP1P Server	4,632	889	19.2%
19 Cyber Security Challenge Germany	4,322	688	15.9%
20 VishwaCTF	4,045	113	2.8%
21 HITCON CTF	4,031	933	23.1%
22 ångstromCTF	4,012	354	8.8%
23 UIUCTF 2026	3,793	523	13.8%
24 Real World CTF	3,754	307	8.2%
25 Midnight Sun CTF	3,730	901	24.2%
26 Hack United	3,534	200	5.7%
27 nullcon HackIM 2026	3,514	168	4.8%
28 ASIS CTF	3,506	705	20.1%
29 UTCTF 2026	3,446	601	17.4%
30 PatriotCTF 2026	3,401	680	20.0%
31 scriptCTF	3,349	609	18.2%
32 HeroCTF	3,267	217	6.6%
33 idekCTF	3,236	594	18.4%
34 247CTF	3,194	203	6.4%
35 NorthSec	3,155	332	10.5%
36 b01lersCTF	3,148	561	17.8%
37 UMassCTF 2026	3,109	549	17.7%
38 SunshineCTF	2,999	358	11.9%
39 BuckeyeCTF 2025	2,964	574	19.4%
40 Kaspersky{CTF}	2,822	353	12.5%
41 KalmarCTF	2,759	719	26.1%
42 corCTF	2,755	536	19.5%
43 Hacking-Lab	2,740	139	5.1%
44 HSCTF	2,647	196	7.4%
45 CrewCTF 2025	2,626	528	20.1%
46 Official HackMyVM	2,621	164	6.3%
47 KnightCTF	2,613	267	10.2%
48 TSG CTF	2,568	240	9.3%
49 smileyCTF 2025	2,530	335	13.2%
50 GPN CTF 2026	2,477	223	9.0%
51 niteCTF '25	2,474	256	10.3%
52 XCTF 10th–SCTF 2026	2,463	185	7.5%
53 rCTF	2,425	203	8.4%
54 Midnight Flag CTF - EXECUTION	2,384	608	25.5%
55 DIVER OSINT CTF	2,355	570	24.2%
56 R3CTF 2026	2,225	535	24.0%
57 HACKTORIA	2,152	272	12.6%
58 UMDCTF 2026	2,136	357	16.7%
59 Hackuten	2,127	199	9.4%
60 1753CTF	2,120	270	12.7%
61 NNS CTF	2,120	592	27.9%
62 b01lers	2,068	203	9.8%
63 CCDC	2,009	390	19.4%
64 HackTheBox_KE	2,006	49	2.4%
65 JerseyCTF 🔒	1,989	280	14.1%
66 DEADFACE CTF	1,957	282	14.4%
67 HackDay	1,939	313	16.1%
68 Hack.lu CTF	1,934	317	16.4%
69 SECCON CTF 14	1,927	606	31.4%
70 Dev Universe - FGTE CTF	1,919	220	11.5%
71 BCACTF	1,915	244	12.7%
72 CTF@CIT	1,888	229	12.1%
73 eCitadel	1,829	326	17.8%
74 jailCTF 2026	1,819	272	15.0%
75 Cyber Odyssey: Akasec CTF	1,804	45	2.5%
76 zer0pts CTF	1,780	262	14.7%
77 InCTF Nationals	1,772	85	4.8%
78 N0PSctf	1,762	187	10.6%
79 SECCON CTF 13	1,733	302	17.4%
80 IrisCTF	1,709	215	12.6%
81 Equinor CTF	1,670	216	12.9%
82 BlahajCTF	1,603	225	14.0%
83 PSU CCSO	1,598	66	4.1%
84 HAXAGON Community	1,557	238	15.3%
85 DamCTF	1,546	164	10.6%
86 pwnable.tw	1,518	166	10.9%
87 ZeroDays CTF	1,478	182	12.3%
88 ECW CTF	1,446	296	20.5%
89 TAMUctf 2026	1,435	216	15.1%
90 TetCTF	1,435	137	9.5%
91 RITSEC CTF	1,420	241	17.0%
92 Reply CTF Challenge	1,397	93	6.7%
93 CyberDawgs Club	1,391	177	12.7%
94 xCTFs	1,375	285	20.7%
95 SECCON CTF 2023	1,367	203	14.9%
96 Sieberrsec CTF	1,315	209	15.9%
97 CyberSpace CTF 2024	1,310	156	11.9%
98 @Hack CTF - Concordia	1,288	155	12.0%
99 CakeCTF 2023	1,281	151	11.8%
100 hackerspace - DropCTF	1,279	192	15.0%
101 ISITDTU-CTF	1,275	137	10.7%
102 SWIMMER OSINT CTF	1,249	225	18.0%
103 Hack In The North	1,242	12	1.0%
104 MontréHack	1,242	185	14.9%
105 WaniCTF	1,232	189	15.3%
106 AlpacaHack	1,224	226	18.5%
107 wpictf	1,188	47	4.0%
108 OmniCTF | Public	1,176	183	15.6%
109 DaVinciCTF	1,159	159	13.7%
110 HKCERT CTF 2024	1,135	189	16.7%
111 Shutlock CTF 🕵	1,131	142	12.6%
112 pingCTF 2026	1,121	125	11.2%
113 RingZer0 CTF	1,119	132	11.8%
114 BDSec CTF	1,119	78	7.0%
115 UnitedCTF	1,107	187	16.9%
116 Swiss Hacking Challenge	1,090	108	9.9%
117 RACTF	1,071	74	6.9%
118 Paradigm CTF	1,066	128	12.0%
119 Olympics CTF	1,063	114	10.7%
120 squ1rrel CTF 2026	1,052	149	14.2%
121 FAUST CTF 2026	1,041	220	21.1%
122 HackTheMidlands	1,039	42	4.0%
123 ZishanHack	1,033	28	2.7%
124 x3CTF 2026	1,031	129	12.5%
125 NCKUCTF	1,030	321	31.2%
126 IRON CTF 2024	1,017	88	8.7%
127 Pragyan CTF'26	1,012	124	12.3%
128 PearlCTF	1,000	97	9.7%
129 SwampCTF	961	117	12.2%
130 Break the Syntax CTF	958	131	13.7%
131 Arab & Africa Regional CTF	948	49	5.2%
132 SpookyCTF	938	99	10.6%
133 BERKE1337	928	113	12.2%
134 Swinburne Cyber Security Club (SCSC)	924	102	11.0%
135 offsec	910	71	7.8%
136 World Wide Hack	907	89	9.8%
137 P3rf3ctr00t CTF	906	56	6.2%
138 BRICS+ CTF	897	81	9.0%
139 pwnable.kr	895	103	11.5%
140 pwntools	895	108	12.1%
141 CyberSecurityRumble	892	99	11.1%
142 Wargames.MY CTF 2024	891	47	5.3%
143 NewbieContest	887	137	15.4%
144 Otaku hunters	833	75	9.0%
145 Wizer CTF	812	53	6.5%
146 Cryptocracy™	795	31	3.9%
147 EnigmaXplore 3.0	794	53	6.7%
148 RPISEC	792	161	20.3%
149 snakeCTF	789	129	16.3%
150 HACK'OSINT - CTF	777	132	17.0%