The cybersecurity API directory
A curated, automatically-updated list of 186 free cybersecurity APIs — threat intelligence, breach & leak checks, DNS/SSL, IP reputation, email verification, authentication and more. Refreshed weekly from the open-source public-API lists, filtered to what actually matters for security work.

Recently added
Anti-Fraud & Phishing (11)
Dymo API
Multi-account and fraud detection. Sending emails without ending up in SPAM
Email Spam Tester
newSend a test message and get a spam score, 41 checks with RFC citations and a fix plan
Email Validation
Validate email addresses for deliverability and spam
FingerprintJS Pro
Fraud detection API offering highly accurate browser fingerprinting
FraudCoins
newOn-chain top-10 holder concentration and contract permissions for crypto tokens
FraudLabs Pro
Screen order information using AI to detect frauds
NoPhishy
Check links to see if they're known phishing attempts
OOPSpam
Multiple spam filtering service
PhishStats
Phishing database
Spam Hunter
Free service to classify text for spam using ML
VeriRoute Intel
CNAM caller ID, carrier/LRN lookup and spam scoring for North American phone numbers
Authentication & Identity (15)
Auth0
Easy to implement, adaptable authentication and authorization platform
Best Temp Mail
newDisposable inboxes for automated email testing, with OTP extraction
CO2 Offset
API calculates and validates the carbon footprint
Climatiq
Calculate the environmental footprint created by a broad range of emission-generating activities
GetOTP
Implement OTP flow quickly
Jumio
Provides identity verification, KYC (Know Your Customer), and AML (Anti-Money Laundering) solutions, including document verification and biometric authentication
LoginRadius
Managed User Authentication Service
Micro User Service
User management and authentication
MojoAuth
Secure and modern passwordless authentication platform
Neetix Liveliness
Face liveness, presentation-attack detection and 1:1 face match for identity verification
SAWO Labs
Simplify login and improve user experience by integrating passwordless authentication in your app
TotalShiftLeft Sandbox
Free multi-protocol sandbox: REST, GraphQL & SOAP with OAuth2/JWT auth and OpenAPI 3.0 spec
Website Carbon
API to estimate the carbon footprint of loading web pages
Xeramail Temp Mail
newTemp email address REST API for privacy, testing, automation with OTP extraction
inboxsink
newDisposable inboxes for end-to-end tests that wait for the email and extract OTP codes
Breach & Leak Intel (4)
ClassiFinder
Detect leaked secrets and prompt-injection in text and return redacted output
HackMyIP
IP geolocation, ISP and privacy/VPN scoring, email breach checks, DNS and WHOIS lookups
HaveIBeenPwned
Passwords which have previously been exposed in data breaches
ThreatCluster
newThreat intelligence: incident clusters, validated IOCs, CVEs, ransomware leak-site victims
Compliance & Privacy (8)
ArcNautical
newScreen any ship by IMO for OFAC/EU/UN/UK sanctions, ownership opacity and a vetting grade
ArcNautical Vessel Check
Vessel sanctions screening, ownership transparency scoring, and vetting intelligence
CompliAPI
newScreen crypto addresses, emails, websites, IDs and countries against OFAC, EU, UK sanctions lists
MediaCraft AI
Chinese content compliance review (17 platforms), EN↔CN translation, and SEO optimization. Pay-per-call via x402 (Solana USDC).
OpenSanctions
Data on international sanctions, crime and politically exposed persons
Privacy.com
Generate merchant-specific and one-time use credit card numbers that link back to your bank
Right to Disconnect
newRight-to-disconnect employment law by EU country: binding status, statute, and sanctions
gankdat
newUK & EU tenders, UK planning, UK sanctions, US exclusions, UK insolvency and incorporations as JSON
Crypto & Secrets (10)
API Snap
Free utility API platform. QR codes, screenshots, PDFs, image resize, hashing, and more
BitWarden
Best open-source password manager
Classify
Encrypting & decrypting text messages
Dehash.lt
Hash decryption MD5, SHA1, SHA3, SHA256, SHA384, SHA512
GitGuardian
Scan files for secrets (API Keys, database credentials)
Hashable
A REST API to access high level cryptographic functions and methods
Passwordinator
Generate random passwords of varying complexities
Secrets-APi
Used For Learning purpose Learn all security types with this api
Utilorax
203 JSON endpoints: hashing, encoding, unit conversion, text, dates and file conversion
dead-drop
Ephemeral zero-knowledge encrypted data sharing
DNS, SSL & Domain (41)
AGPC Domain Check
Check a domain's SPF, DKIM, DMARC and MX with a graded shareable report
APIFreaks
API hub with DNS, WHOIS, Screenshot, IP Geolocation, Weather, Commodity & Currency APIs
Alpha (Mossland)
Korean crypto channel stance + RAG Q&A + canonical entity/topic/event store
CSR.plus
Generate certificate signing requests and private keys without OpenSSL
Cloudflare
Manage DNS, CDN, Workers and other services; documented with an official OpenAPI 3.0 spec
Cloudflare Trace
Get IP Address, Timestamp, User Agent, Country Code, IATA, HTTP Version, TLS/SSL Version & More
Cloudmersive Validate
Validate email addresses, phone numbers, VAT numbers and domain names
Compresso
newVisually lossless image compression for PNG, JPEG and WebP
Creative Commons Catalog
Search among openly licensed and public domain works
DigMyName
Domain availability and registrar pricing across 52 TLDs
Domain Intelligence
DNS, WHOIS/RDAP, SSL, subdomain enumeration, and email security in one parallel call
DomainDb Info
Domain name search to find all domains containing particular words/phrases/etc
Domainsdb.info
Registered Domain Names Search
FontDownloader
A hassle free API for managing web fonts provided by Google Fonts
Google Safe Browse
Google Link/Domain Flagging
Google Safe Browsing
Google Link/Domain Flagging
Host.io
Domains Data API for Developers
IP2WHOIS Hosted Domain Lookup
WHOIS domain name and hosted domain lookup
IP2WHOIS Information Lookup
WHOIS domain name lookup
IPFinder
Geolocation API,ASN API,IP Ranges API,IP Firewall API,Domain API
Is This Site Down?
newCheck if any website is down, from two continents; live status, uptime history and TLS expiry
JSON 2 JSONP
Convert JSON to JSONP (on-the-fly) for easy cross-domain data requests using client-side JavaScript
Kiprio SSL Inspector
TLS certificate analysis with protocol matrix, cipher suite and HSTS grading
Lix.li
newURL shortener with analytics, QR codes, UTM tags and custom domains
Mockerito
Free mock REST APIs across different business domains
Mozilla tls scanner
Mozilla observatory tls scanner
NetworkCalc
Network calculators, including subnets, DNS, binary, and security tools
PositiveQuotation
newSource-verified public-domain English proverbs with provenance
RedirHub
URL redirect management with custom domains, HTTPS, analytics, and REST API
SSL Domain Health Check
SSL certificate validity, domain WHOIS status, and DNS record checks for any domain
SSL Labs
Deep SSL/TLS server analysis with A+ to F grading
SecurityTrails
Domain and IP related information such as current and historical WHOIS and DNS records
Short Link
Short URLs support so many domains
Shrtcode
URl Shortener with multiple Domains
Sonar
Project Sonar DNS Enumeration API
Universities List
University names, countries and domains
dotsweep
Domain availability across 1200+ TLDs with registration and renewal prices
host-t.com
Basic DNS query via HTTP GET request
ip-api
Find location with IP address or domain
ipfind.io
Geographic location of an IP address or any domain name along with some other useful information
ipwhois
IP geolocation with country, city, coordinates, ISP, timezone and flag data
Email Verification (12)
Abstract API
Suite of APIs including email validation, IP geolocation, phone validation, exchange rates and more
Hunter
API for domain search, professional email finder, author finder and email verifier
Kickbox
Email verification API
Kiprio Email Validate
Free email validation: MX check, disposable detection, syntax
Kiprio Email Validation
Email address validation with MX, disposable, role and typo detection
Mailsac
Disposable Email
Meirra
SEO monitoring, email verification, lead generation, and marketing analytics
Micro-SaaS AI Suite
8 serverless AI APIs for sentiment analysis, copy generation, email verification, & OCR
Signaliz
GTM enrichment, lead generation, email verification, and company signals
SpryTools Email Validation
Syntax + MX + disposable/role-based email validation
Tomba email finder
Email Finder for B2B sales and email marketing and email verifier
uchecker
Bulk email verification with full SMTP server responses
IP Intelligence (18)
Airtel IP
IP Geolocation API. Collecting data from multiple sources
Airtel IP
IP Geolocation API. Collecting data from multiple sources
ApogeoAPI
Bundled API for countries, states, cities, IP geolocation, and live exchange rates
BigDataCloud
Provides fast and accurate IP geolocation APIs along with security checks and confidence area
FreeGeoIP
Free geo ip information, no registration required. 15k/hour rate limit
GeoJS
IP geolocation with ChatOps integration
Geolocated.io
Free IP Geolocation API: 2000 daily lookups, multiple servers worldwide
IP Geolocation
Geolocate website visitors from their IPs
IP Vigilante
Free IP Geolocation API
IP2Location
IP geolocation web service to get more than 55 parameters
IP2Location.io
Free IP geolocation API to geolocate user's location information
IP99
newIP geolocation with proxy, VPN and datacenter risk and the age of the evidence
Unblock Master IP
newIP geolocation plus datacenter and VPN detection for any IPv4 or IPv6 address
geoPlugin
IP geolocation and currency conversion
ipgeolocation
IP Geolocation AP with free plan 30k requests per month
ipgeolocation
Find geolocation of any IP address with IP Geolocation API
keycdn IP Location Finder
Get the IP geolocation data through the simple REST API. All the responses are JSON encoded
sthan.io IP Geolocation
newLook up the geographic location of any IPv4 or IPv6 address
Security (32)
Application Environment Verification
Android library and API to verify the safety of user devices, detect rooted devices and other risks
BinaryEdge
Provide access to BinaryEdge 40fy scanning platform
Blooms
Distribute keys once for serverless applications
Botd
Botd is a browser library for JavaScript bot detection
Bugcrowd
Bugcrowd API for interacting and tracking the reported issues programmatically
CRXcavator
Chrome extension risk scoring
CVE.report
CVE records with NVD KEV and EPSS enrichment
Censys
Search engine for Internet connected host and devices
Complete Criminal Checks
Provides data of offenders from all U.S. States and Pureto Rico
Escape
An API for escaping different kind of queries
FOFA
Search engine for Internet connected assets and devices
FilterLists
Lists of filters for adblockers and firewalls
FishFish
A volunteer cybersecurity project focused on providing resources and services that improve safety across Discord
FullHunt
Searchable attack surface database of the entire internet
GreyNoise
Query IPs in the GreyNoise dataset and retrieve a subset of the full IP context data
HackerOne
The industry’s first hacker API that helps increase productivity towards creative bug bounty hunting
IPLogs
Free VPN, proxy, Tor and datacenter IP detection. 13 sources, active probing
Maskbreak
newDetect VPNs, proxies, Tor, bots and antidetect browsers at signup, login and checkout
Metacert
Metacert Link Flagging
Microsoft Security Response Center (MSRC)
Programmatic interfaces to engage with the Microsoft Security Response Center (MSRC)
Mozilla http scanner
Mozilla observatory http scanner
National Vulnerability Database
U.S. National Vulnerability Database
Portscan
Scans the requesting client's IP for open TCP ports with fast or deep modes on IPv4/IPv6
Sealed Rose
newAI media forensics and synthetic content verification for video, audio, image, and text
Shodan
Search engine for Internet connected devices
Spyse
Access data on all Internet assets and build powerful attack surface management applications
UK Police
UK Police data
URLScan.io
Scan and Analyse URLs
VirusTotal
VirusTotal File/URL Analysis
VirusTotal
VirusTotal File/URL Analysis
Virushee
Virushee file/data scanning
VulDB
VulDB API allows to initiate queries for one or more items along with transactional bots
Security Utilities (3)
Threat Intelligence (32)
AbuseIPDB
IP/domain/URL reputation
AlienVault Open Threat Exchange (OTX)
IP/domain/URL reputation
CAPEsandbox
Malware execution and analysis
EmailRep
Email address threat and risk prediction
Hybrid Analysis
File and URL malware analysis powered by Falcon Sandbox
IP-API.io
IP geolocation with VPN/proxy/Tor detection, reputation and risk score
IPASIS
Real-time bot detection and fraud prevention API combining IP reputation, proxy/VPN detection, and email validation in a single call
IPGuardian
newCheck IP addresses against 140+ public threat intelligence blocklists
IPLocate.io
Fast, free, accurate IP geolocation and threat data (proxy/VPN/hosting detection) API
IPWhois.net Blacklist
Community IP blacklist to check and report abusive IP addresses
IPstack MCP
newIP geolocation, threat and timezone lookups for agents
Intelligence X
Perform OSINT via Intelligence X
Kiprio IP Lookup
IP geolocation and reputation with proxy, VPN, and hosting detection
MadeOnSol
newReal-time Solana & Robinhood Chain KOL trades, deployer reputation, and DEX activity
MalDatabase
Provide malware datasets and threat intelligence feeds
MalShare
Malware Archive / file sourcing
Malwagon
newDetonates files and URLs in instrumented VMs and returns behaviour, IOCs and ATT&CK
MalwareBazaar
Collect and share malware samples
Pharos API
Stablecoin risk, peg, liquidity, safety score, blacklist, mint/burn, yield, and chain-health data
Phisherman
IP/domain/URL reputation
Presend
newSecurity and developer utility API -- malware, vulnerability, and domain checks, no signup
Pulsedive
Scan, search and collect threat intelligence data in real-time
ScanMalware
newScan URLs in a sandboxed browser and search past scans by domain, IP, ASN, JARM or favicon hash
Scanii
Simple REST API that can scan submitted documents/files for the presence of threats
Threat Jammer
Risk scoring service from curated threat intelligence data
URLhaus
Bulk queries and Download Malware Samples
URLhaus
Database of malicious URLs used for malware distribution
Web Of Trust (WOT)
Website reputation
Web of Trust
IP/domain/URL reputation
WhoisJSONApi
Domain WHOIS information to detect and prevent online threats, enhancing overall online safety for individuals and organizations
Whoisfreaks
Domain and DNS related information that will equip organizaion with comprehensive threat intelligence and attack surface analysis capabilities for enhanced security
ipgeolocationapi
newIP geolocation with ASN, timezone, currency and threat data, 5,000 keyless calls a day
Build your security program, not just call APIs
PlayCISO turns security decisions into practice — a War Room incident simulator, breach-cost modelling, and free scanners for your stack.
Entries are sourced from community-maintained open lists (public-apis, public-api-lists) and filtered for security relevance. Listings are informational; verify each provider's terms before use.