Công cụ trực tuyến miễn phí
268+ free online tools for PDF, images, SEO, developers, color, and productivity. Fast, browser-based, and private — no signup, no installs, no limits. Search above or browse by category below.
Total tools26810.8K total uses
Categories13Active categories
Most usedJSON Formatter4.1K uses
Recently addedExperiment RandomizerNewest tool
Password Strength Checker
Analyze password strength with entropy estimates, crack-time projections, and improvement tips.
Used 0 times•Updated never
AES Encrypt
Encrypt and decrypt text with AES-GCM or AES-CBC using a passphrase or hex key, entirely in your browser.
Used 0 times•Updated never
AES Decrypt
Decrypt AES-GCM or AES-CBC JSON payloads using the passphrase or hex key that was used to encrypt them.
Used 0 times•Updated never
SSL Checker
Inspect TLS certificates for any public hostname — expiry, issuer, chain, cipher, and hostname match.
Used 0 times•Updated never
SSL Expiry Checker
Check when a website SSL certificate expires. See days remaining, expiry date, chain validity, and renewal recommendations.
Used 0 times•Updated never
DNS Lookup
Query public DNS records for any domain — A, AAAA, MX, TXT, NS, CNAME, SOA, SRV, CAA, and PTR.
Used 0 times•Updated never
DMARC Checker
Look up and parse DMARC DNS records for a domain. Review policy, reporting tags, and SPF alignment hints.
Used 0 times•Updated never
IP Address Lookup
Look up geolocation, ISP, ASN, reverse DNS, and IP format details for any public IPv4 or IPv6 address.
Used 0 times•Updated never
Reverse DNS Lookup
Look up PTR reverse DNS records for a public IP address. Resolve hostnames and verify forward DNS (FCrDNS) alignment.
Used 0 times•Updated never
DNS Propagation Checker
Check DNS record propagation across global public resolvers. Compare answers from Google, Cloudflare, Quad9, and more.
Used 0 times•Updated never
Subnet Calculator
Calculate IPv4 subnet details from CIDR notation or a subnet mask. Get network, broadcast, and host ranges instantly.
Used 0 times•Updated never
CIDR Calculator
Analyze CIDR blocks, convert prefix lengths to subnet masks, split networks, and check whether an IP belongs to a range.
Used 0 times•Updated never