Curated Collection
Free Security · Free
This page picks 200 fully free or with a free tier Security Tools, ranked by overall rating and price, with an average rating of 8.3 / 10. 135 of them are friendly for mainland China access (CN ≥ 2 stars). Monthly prices range from $2.99 to $499. Headquarters: United States / International / Germany / Unknown. Data is compiled from public sources plus editorial testing, cached and refreshed every 5 minutes; compare specs and jump straight to official sites in the table below.
Category
🛡 All Security
Free Security Top 9
Sorted by this dimension, recalibrated monthlyAll 200 Free Security compared
Click a provider name for the full review| # | Provider | Sub-category | HQ | Monthly | Rating | CN | Payment | Visit |
|---|---|---|---|---|---|---|---|---|
| 1 |
 letsencrypt.org |
SSL Certificate | United States | Free / Contact | 9.9 | — | Visit | |
| 2 |
 1password.com |
密码管理器 | Canada | $2.99/mo | 9.0 | — | Visit | |
| 3 |
 adguard.com |
广告拦截 | Cyprus | Free / Contact | 9.0 | — | Visit | |
| 4 |
 logto.io |
身份认证/SSO | United States | Free / Contact | 9.0 | — | Visit | |
| 5 |
 opensecurityarchitecture.org |
Security Patterns | United Kingdom | Free / Contact | 9.0 | — | Visit | |
| 6 |
 robtex.com |
网络情报 | United States | Free / Contact | 9.0 | — | Visit | |
| 7 |
 2fas.com |
2Fa Authenticator | Poland | Free / Contact | 9.0 | — | Visit | |
| 8 |
A auth0.com |
身份认证平台 | United States | Free / Contact | 9.0 | — | Visit | |
| 9 |
 cryptomator.org |
文件加密 | Germany | Free / Contact | 9.0 | — | Visit | |
| 10 |
 mojoauth.com |
Passwordless Auth | United States | Free / Contact | 9.0 | — | Visit | |
| 11 |
 seon.io |
Fraud Prevention | United States | Free / Contact | 9.0 | — | Visit | |
| 12 |
U ublock.org |
广告拦截插件 | United States | Free / Contact | 9.0 | — | Visit | |
| 13 |
C cloudsecurityalliance.org |
云安全认证 | United States | Free / Contact | 9.0 | — | Visit | |
| 14 |
 cyclonedx.org |
软件供应链安全标准 | International | Free / Contact | 9.0 | — | Visit | |
| 15 |
 domaintools.com |
Threat Intelligence | United States | Free / Contact | 9.0 | — | Visit | |
| 16 |
 gnupg.org |
加密工具 | Global | Free / Contact | 9.0 | — | Visit | |
| 17 |
 gpg4win.org |
Encryption | Germany | Free / Contact | 9.0 | — | Visit | |
| 18 |
 grapheneos.org |
移动系统安全 | United States | Free / Contact | 9.0 | — | Visit | |
| 19 |
 haveibeenpwned.com |
Data Breach Check | Australia | Free / Contact | 9.0 | — | Visit | |
| 20 |
 honggfuzz.dev |
模糊测试 | United States | Free / Contact | 9.0 | — | Visit | |
| 21 |
I imperva.com |
Cybersecurity | United States | Free / Contact | 9.0 | — | Visit | |
| 22 |
I internationalsos.com |
Travel Risk Management | Singapore | Free / Contact | 9.0 | — | Visit | |
| 23 |
 keepass.info |
密码管理器 | Global | Free / Contact | 9.0 | — | Visit | |
| 24 |
 keepassxc.org |
密码管理器 | Global | Free / Contact | 9.0 | — | Visit | |
| 25 |
 modsecurity.org |
Web Application Firewall | International | Free / Contact | 9.0 | — | Visit | |
| 26 |
 noscript.net |
浏览器安全扩展 | United States | Free / Contact | 9.0 | — | Visit | |
| 27 |
 ossec.net |
主机入侵检测 | United States | Free / Contact | 9.0 | — | Visit | |
| 28 |
 pfsense.org |
Firewall | United States | Free / Contact | 9.0 | — | Visit | |
| 29 |
 pki.goog |
证书颁发机构 | United States | Free / Contact | 9.0 | — | Visit | |
| 30 |
 securelist.com |
威胁情报 | Russia | Free / Contact | 9.0 | — | Visit | |
| 31 |
 securityscorecard.com |
Cyber Risk Rating | United States | Free / Contact | 9.0 | — | Visit | |
| 32 |
S snyk.io |
Application Security | United States | Free / Contact | 9.0 | — | Visit | |
| 33 |
 splunk.com |
Siem | United States | Free / Contact | 9.0 | — | Visit | |
| 34 |
 stopforumspam.com |
Spam Prevention | United States | Free / Contact | 9.0 | — | Visit | |
| 35 |
 talosintelligence.com |
Threat Intelligence | United States | Free / Contact | 9.0 | — | Visit | |
| 36 |
 zeek.org |
网络安全监控 | United States | Free / Contact | 9.0 | — | Visit | |
| 37 |
O ooni.org |
Network Censorship Measurement | International | Free / Contact | 9.0 | — | Visit | |
| 38 |
 privacybadger.org |
浏览器隐私插件 | United States | Free / Contact | 9.0 | — | Visit | |
| 39 |
U ublockorigin.com |
广告拦截 | Canada | Free / Contact | 9.0 | — | Visit | |
| 40 |
B bitwarden.eu |
密码管理器 | United States | Free / Contact | 9.0 | — | Visit | |
| 41 |
B blocksec.com |
Web3安全审计监控 | China | Free / Contact | 9.0 | — | Visit | |
| 42 |
C clerk.com |
开发者认证用户管理 | United States | Free / Contact | 9.0 | — | Visit | |
| 43 |
C cybexer.com |
Cyber Range安全演练平台 | Estonia | Free / Contact | 9.0 | — | Visit | |
| 44 |
D dexidp.io |
开源OIDC身份提供商 | United States | Free / Contact | 9.0 | — | Visit | |
| 45 |
F freessl.cn |
免费HTTPS证书申请 | China | Free / Contact | 9.0 | — | Visit | |
| 46 |
D duna.com |
KYB/KYC/AML合规 | United Kingdom | Free / Contact | 9.0 | — | Visit | |
| 47 |
E easy.ac |
游戏反作弊 | Finland | Free / Contact | 9.0 | — | Visit | |
| 48 |
F falco.org |
云原生运行时安全 | United States | Free / Contact | 9.0 | — | Visit | |
| 49 |
F feedzai.com |
金融反欺诈风控 | Portugal | Free / Contact | 9.0 | — | Visit | |
| 50 |
F fusionauth.io |
CIAM/身份认证 | United States | Free / Contact | 9.0 | — | Visit | |
| 51 |
S seedsecuritylabs.org |
网络安全实验课程 | United States | Free / Contact | 9.0 | — | Visit | |
| 52 |
T trufflesecurity.com |
密钥泄露检测 | United States | Free / Contact | 9.0 | — | Visit | |
| 53 |
P pangea.cloud |
AI应用安全API | United States | Free / Contact | 9.0 | — | Visit | |
| 54 |
S saif.google |
AI安全框架 | United States | Free / Contact | 9.0 | — | Visit | |
| 55 |
S shield.com |
设备指纹/反欺诈平台 | Singapore | Free / Contact | 9.0 | — | Visit | |
| 56 |
S spiffe.io |
Workload Identity | United States | Free / Contact | 9.0 | — | Visit | |
| 57 |
T trivy.dev |
开源漏洞与容器安全扫描 | Japan | Free / Contact | 9.0 | — | Visit | |
| 58 |
 aiemailgenie.com |
Email Security | United States | $9.99/mo | 8.0 | — | Visit | |
| 59 |
P pulsedive.com |
威胁情报平台 | United States | $29.00/mo | 8.0 | — | Visit | |
| 60 |
F falconfeeds.io |
Threat Intelligence | India | $499.00/mo | 8.0 | — | Visit | |
| 61 |
G gpgtools.org |
邮件与文件加密 | United States | Free / Contact | 8.0 | — | Visit | |
| 62 |
 443id.com |
Identity Threat Detection | United States | Free / Contact | 8.0 | — | Visit | |
| 63 |
 coinsult.net |
Smart Contract Audit | Netherlands | Free / Contact | 8.0 | — | Visit | |
| 64 |
 multiotp.net |
Two Factor Auth | 开源项目 | Free / Contact | 8.0 | — | Visit | |
| 65 |
 aamportal.com |
WordPress访问控制 | United States | Free / Contact | 8.0 | — | Visit | |
| 66 |
 activefence.com |
AI安全与信任 | United States | Free / Contact | 8.0 | — | Visit | |
| 67 |
 dnscrypt.info |
DNS加密协议 | United States | Free / Contact | 8.0 | — | Visit | |
| 68 |
 feedly.com |
威胁情报 | United States | Free / Contact | 8.0 | — | Visit | |
| 69 |
F fortanix.com |
数据安全平台 | United States | Free / Contact | 8.0 | — | Visit | |
| 70 |
 friendlycaptcha.com |
Bot Protection | Germany | Free / Contact | 8.0 | — | Visit | |
| 71 |
 invariantlabs.ai |
AI安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 72 |
 malwarebytes.com |
杀毒防护 | United States | Free / Contact | 8.0 | — | Visit | |
| 73 |
 nordpass.com |
Password Mgr | Panama | Free / Contact | 8.0 | — | Visit | |
| 74 |
 really-simple-ssl.com |
Wordpress Security Plugin | Netherlands | Free / Contact | 8.0 | — | Visit | |
| 75 |
S socialcatfish.com |
People Search | United States | Free / Contact | 8.0 | — | Visit | |
| 76 |
 surbl.org |
Reputation Data | United States | Free / Contact | 8.0 | — | Visit | |
| 77 |
 fingerprint.com |
Device Fingerprinting | United States | Free / Contact | 8.0 | — | Visit | |
| 78 |
 hardenize.com |
Network Security Monitoring | United States | Free / Contact | 8.0 | — | Visit | |
| 79 |
 pwpush.com |
Password Sharing | United States | Free / Contact | 8.0 | — | Visit | |
| 80 |
 rethinkdns.com |
DNS防火墙 | United States | Free / Contact | 8.0 | — | Visit | |
| 81 |
 soemailsecurity.com |
邮件安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 82 |
 spur.us |
Ip Intelligence | United States | Free / Contact | 8.0 | — | Visit | |
| 83 |
 stytch.com |
身份认证API | United States | Free / Contact | 8.0 | — | — | Visit |
| 84 |
 0-patch.com |
Vulnerability Patching | Slovenia | Free / Contact | 8.0 | — | Visit | |
| 85 |
 0-patch.net |
Vulnerability Patching | Slovenia | Free / Contact | 8.0 | — | Visit | |
| 86 |
 0patch.com |
Vulnerability Patching | Slovenia | Free / Contact | 8.0 | — | Visit | |
| 87 |
 1id.biz |
AI身份 | United States | Free / Contact | 8.0 | — | Visit | |
| 88 |
 1id.com |
AI身份 | United States | Free / Contact | 8.0 | — | Visit | |
| 89 |
2 2favault.app |
2FA认证 | United States | Free / Contact | 8.0 | — | Visit | |
| 90 |
4stop.com |
KYC/反欺诈 | United States | Free / Contact | 8.0 | — | Visit | |
| 91 |
 activitylog.io |
Wordpress Plugin | Unknown | Free / Contact | 8.0 | — | Visit | |
| 92 |
 adaptive.live |
AI代理安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 93 |
 adaway.org |
广告拦截 | International | Free / Contact | 8.0 | — | Visit | |
| 94 |
 adguard.info |
广告拦截 | Cyprus | Free / Contact | 8.0 | — | Visit | |
| 95 |
 adpocalypse.net |
广告拦截扩展 | United Kingdom | Free / Contact | 8.0 | — | Visit | |
| 96 |
 advisoryweek.com |
漏洞情报 | Unknown | Free / Contact | 8.0 | — | Visit | |
| 97 |
A aegis-web4.com |
Data Leak Prevention | United States | Free / Contact | 8.0 | — | Visit | |
| 98 |
 aerobase.io |
IAM平台 | United States | Free / Contact | 8.0 | — | Visit | |
| 99 |
 afip.org |
内容取证 | United States | Free / Contact | 8.0 | — | Visit | |
| 100 |
 againstphishing.org |
反钓鱼 | International | Free / Contact | 8.0 | — | Visit | |
| 101 |
 agilicus.com |
Zero Trust Network Access | Canada | Free / Contact | 8.0 | — | Visit | |
| 102 |
 ail-project.org |
威胁情报 | International | Free / Contact | 8.0 | — | Visit | |
| 103 |
 aiologin.com |
Wordpress Login Security | United States | Free / Contact | 8.0 | — | Visit | |
| 104 |
A aisle.com |
应用安全平台 | United States | Free / Contact | 8.0 | — | Visit | |
| 105 |
 ajax.systems |
安防报警 | Ukraine | Free / Contact | 8.0 | — | Visit | |
| 106 |
A alarm.com |
安防监控 | United States | Free / Contact | 8.0 | — | — | Visit |
| 107 |
 alice.io |
Ai Trust Safety | United States | Free / Contact | 8.0 | — | Visit | |
| 108 |
 altcha.org |
Captcha Bot Protection | 开源项目 | Free / Contact | 8.0 | — | Visit | |
| 109 |
 alwaysfurther.ai |
AI安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 110 |
 appomni.com |
SaaS安全 | United States | Free / Contact | 8.0 | — | — | Visit |
| 111 |
 av-comparatives.org |
安全评测认证 | Austria | Free / Contact | 8.0 | — | Visit | |
| 112 |
 bigid.com |
数据安全平台 | United States | Free / Contact | 8.0 | — | Visit | |
| 113 |
B binarydefense.com |
MDR托管检测响应 | United States | Free / Contact | 8.0 | — | Visit | |
| 114 |
 botscout.com |
机器人检测 | United States | Free / Contact | 8.0 | — | Visit | |
| 115 |
 calyxos.org |
移动隐私系统 | United States | Free / Contact | 8.0 | — | Visit | |
| 116 |
 camflow.org |
系统审计与数据溯源 | United Kingdom | Free / Contact | 8.0 | — | Visit | |
| 117 |
 canokeys.org |
硬件安全密钥 | Hong Kong | Free / Contact | 8.0 | — | Visit | |
| 118 |
 checkmarx.com |
Application Security | United States | Free / Contact | 8.0 | — | Visit | |
| 119 |
 cheq.ai |
流量安全与反欺诈 | United States | Free / Contact | 8.0 | — | Visit | |
| 120 |
 claroty.com |
OT安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 121 |
 connect2id.com |
OpenID Connect/OAuth 2.0服务器 | Australia | Free / Contact | 8.0 | — | Visit | |
| 122 |
 content-security-policy.com |
Web安全文档 | United States | Free / Contact | 8.0 | — | Visit | |
| 123 |
 corbado.com |
Passkey Authentication | United States | Free / Contact | 8.0 | — | — | Visit |
| 124 |
C cyble.com |
Threat Intelligence | United States | Free / Contact | 8.0 | — | Visit | |
| 125 |
C cyware.com |
Threat Intelligence | United States | Free / Contact | 8.0 | — | Visit | |
| 126 |
 delinea.com |
身份安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 127 |
 devolutions.net |
Remote Access & Password Management | Canada | Free / Contact | 8.0 | — | Visit | |
| 128 |
 dkim.org |
Email Authentication | United States | Free / Contact | 8.0 | — | Visit | |
| 129 |
 dmarcian.com |
Dmarc Management | United States | Free / Contact | 8.0 | — | Visit | |
| 130 |
 endace.com |
Network Security | New Zealand | Free / Contact | 8.0 | — | Visit | |
| 131 |
 evolveum.com |
Identity Governance | Czechia | Free / Contact | 8.0 | — | Visit | |
| 132 |
F f5.com |
Application Security | United States | Free / Contact | 8.0 | — | Visit | |
| 133 |
 faircode.eu |
移动隐私防护 | Netherlands | Free / Contact | 8.0 | — | Visit | |
| 134 |
 fidoalliance.org |
Authentication Standard | United States | Free / Contact | 8.0 | — | Visit | |
| 135 |
 firewalla.com |
Network Firewall | United States | Free / Contact | 8.0 | — | Visit | |
| 136 |
 flowcrypt.com |
Email Encryption | United States | Free / Contact | 8.0 | — | Visit | |
| 137 |
G getadblock.com |
广告拦截 | United States | Free / Contact | 8.0 | — | Visit | |
| 138 |
 gnutls.org |
TLS库 | Global | Free / Contact | 8.0 | — | Visit | |
| 139 |
 grc.com |
端口安全检测 | United States | Free / Contact | 8.0 | — | Visit | |
| 140 |
 grsecurity.net |
Linux Kernel Security | United States | Free / Contact | 8.0 | — | Visit | |
| 141 |
G guardianproject.info |
Mobile Security | United States | Free / Contact | 8.0 | — | Visit | |
| 142 |
 guardsquare.com |
Mobile App Security | Belgium | Free / Contact | 8.0 | — | Visit | |
| 143 |
G gvisor.dev |
Container Security | United States | Free / Contact | 8.0 | — | Visit | |
| 144 |
 heimdalsecurity.com |
网络安全平台 | Denmark | Free / Contact | 8.0 | — | Visit | |
| 145 |
honeynet.org |
蜜罐与威胁研究 | United States | Free / Contact | 8.0 | — | Visit | |
| 146 |
 hstspreload.org |
HTTPS安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 147 |
 idnow.io |
身份验证KYC | Germany | Free / Contact | 8.0 | — | — | Visit |
| 148 |
 kinde.com |
Authentication & Billing | United States | Free / Contact | 8.0 | — | Visit | |
| 149 |
 kismetwireless.net |
无线安全嗅探 | United States | Free / Contact | 8.0 | — | Visit | |
| 150 |
 libreswan.org |
VPN软件 | United States | Free / Contact | 8.0 | — | Visit | |
| 151 |
 mimecast.com |
邮件与协作安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 152 |
N nsslabs.com |
安全测试验证 | United States | Free / Contact | 8.0 | — | Visit | |
| 153 |
 obdev.at |
Firewall | Austria | Free / Contact | 8.0 | — | Visit | |
| 154 |
 onetimesecret.com |
一次性秘密分享 | United States | Free / Contact | 8.0 | — | Visit | |
| 155 |
 openssl.org |
加密库与TLS | United States | Free / Contact | 8.0 | — | Visit | |
| 156 |
 opnsense.org |
Firewall | United States | Free / Contact | 8.0 | — | Visit | |
| 157 |
 pipl.com |
Fraud Intelligence | United States | Free / Contact | 8.0 | — | — | Visit |
| 158 |
 pinkerton.com |
企业安全风险咨询 | United States | Free / Contact | 8.0 | — | Visit | |
| 159 |
P privatebin.net |
加密文本分享 | Unknown | Free / Contact | 8.0 | — | Visit | |
| 160 |
 projecthoneypot.org |
Anti Spam | United States | Free / Contact | 8.0 | — | Visit | |
| 161 |
R regulaforensics.com |
Identity Verification | Belarus | Free / Contact | 8.0 | — | Visit | |
| 162 |
 safety.google |
安全与隐私中心 | United States | Free / Contact | 8.0 | — | Visit | |
| 163 |
 safenet-inc.com |
数据安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 164 |
 sardine.ai |
金融犯罪防护平台 | United States | Free / Contact | 8.0 | — | — | Visit |
| 165 |
 securiti.ai |
Data Security | United States | Free / Contact | 8.0 | — | Visit | |
| 166 |
 securitytxt.org |
漏洞披露 | International | Free / Contact | 8.0 | — | Visit | |
| 167 |
 self.xyz |
数字身份验证 | United States | Free / Contact | 8.0 | — | — | Visit |
| 168 |
S shadowserver.org |
威胁情报 | United States | Free / Contact | 8.0 | — | Visit | |
| 169 |
 spdx.dev |
软件供应链安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 170 |
T theupdateframework.io |
软件供应链安全 | United States | Free / Contact | 8.0 | — | Visit | |
| 171 |
U userify.com |
Ssh Key Management | United States | Free / Contact | 8.0 | — | Visit | |
| 172 |
 virtru.com |
Data Encryption | United States | Free / Contact | 8.0 | — | — | Visit |
| 173 |
 0xkyc.id |
Zero Knowledge Identity Verification | United States | Free / Contact | 8.0 | — | Visit | |
| 174 |
 1blocker.com |
广告拦截 | United States | Free / Contact | 8.0 | — | Visit | |
| 175 |
 280blocker.net |
广告拦截 | Japan | Free / Contact | 8.0 | — | Visit | |
| 176 |
 360.com |
Cybersecurity | China | Free / Contact | 8.0 | — | Visit | |
| 177 |
3 360.net |
企业网络安全 | China | Free / Contact | 8.0 | — | Visit | |
| 178 |
 4otp.com |
2Fa Authenticator | Unknown | Free / Contact | 8.0 | — | Visit | |
| 179 |
 ad-ninja.net |
广告拦截 | Germany | Free / Contact | 8.0 | — | Visit | |
| 180 |
A adblockplus.org |
广告拦截 | Germany | Free / Contact | 8.0 | — | Visit | |
| 181 |
 ainita.net |
网络安全研究 | United States | Free / Contact | 8.0 | — | Visit | |
| 182 |
 apparmor.net |
Linux访问控制 | United States | Free / Contact | 8.0 | — | Visit | |
| 183 |
 checkra.in |
越狱工具 | United States | Free / Contact | 8.0 | — | Visit | |
| 184 |
 dban.org |
数据擦除 | United States | Free / Contact | 8.0 | — | Visit | |
| 185 |
 netfilter.org |
Firewall | International | Free / Contact | 8.0 | — | Visit | |
| 186 |
 openpgpjs.org |
加密库 | Switzerland | Free / Contact | 8.0 | — | Visit | |
| 187 |
 openldap.org |
身份目录 | United States | Free / Contact | 8.0 | — | Visit | |
| 188 |
O opensanctions.org |
制裁名单数据库 | International | Free / Contact | 8.0 | — | Visit | |
| 189 |
P psonoo.com |
Password Mgr | Germany | Free / Contact | 8.0 | — | Visit | |
| 190 |
 sandboxie-plus.com |
Sandbox Software | 开源（开发者奥地利） | Free / Contact | 8.0 | — | Visit | |
| 191 |
 stoutner.com |
隐私浏览器 | United States | Free / Contact | 8.0 | — | Visit | |
| 192 |
 tella-app.org |
Encrypted Documentation | United States | Free / Contact | 8.0 | — | Visit | |
| 193 |
2faapp.com |
2FA工具与指南 | United States | Free / Contact | 8.0 | — | Visit | |
| 194 |
 a.ai |
Web Security | United States | Free / Contact | 8.0 | — | Visit | |
| 195 |
 a13e.com |
云安全平台 | United States | Free / Contact | 8.0 | — | Visit | |
| 196 |
A activethreathunting.io |
Threat Hunting | Unknown | Free / Contact | 8.0 | — | Visit | |
| 197 |
A addressregistrar.com |
Domain Reputation | United States | Free / Contact | 8.0 | — | Visit | |
| 198 |
A agewallet.com |
Age Assurance | United States | Free / Contact | 8.0 | — | — | Visit |
| 199 |
A amibeingpwned.com |
Browser Extension Security | United States | Free / Contact | 8.0 | — | Visit | |
| 200 |
A amplify.security |
Ai Security | United States | Free / Contact | 8.0 | — | Visit |
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