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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 tools26810.9K total uses
Categories13Active categories
Most usedJSON Formatter4.1K uses
Recently addedExperiment RandomizerNewest tool
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
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
SPF Record Checker
Look up and validate SPF TXT records for a domain. Parse mechanisms, count DNS lookups, and review policy strength.
Used 0 times•Updated never
Port Scanner
Scan common TCP ports on a public host — check which services are reachable from the server.
Used 0 times•Updated never
Ping Test
Ping a hostname or IP from the server. Check reachability, packet loss, and round-trip latency.
Used 0 times•Updated never
Website Uptime Checker
Check if a website is online from the server. See HTTP status, response time, redirects, and key response headers.
Used 0 times•Updated never
HTTP Header Checker
Inspect HTTP response headers for any URL. Review security headers, caching directives, CORS, and server metadata.
Used 0 times•Updated never
User Agent Parser
Parse user agent strings to identify browser, engine, operating system, device type, and bot detection.
Used 0 times•Updated never
Diff Checker
Compare two texts and highlight added, removed, and changed lines or words instantly in your browser.
Used 0 times•Updated never
API Tester
Send HTTP requests with custom methods, headers, and bodies, then inspect status, headers, and response — no CORS limits.
Used 0 times•Updated never