Developer Tools
Format, encode, decode and generate the small things developers handle every day. Everything runs in your browser.
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JSON Formatter & Validator
Pretty-print, minify and validate JSON, with clear error messages that point to the line and column. -
Base64 Encoder & Decoder
Encode text to Base64 and decode it back, with full UTF-8 support and the URL-safe alphabet. -
URL Encoder & Decoder
Percent-encode text for URLs and decode encoded strings, with a breakdown of a URL’s parts and query parameters. -
UUID Generator
Generate random version 4 or time-ordered version 7 UUIDs with your browser’s secure random generator, and inspect any UUID. -
Unix Timestamp Converter
Convert Unix timestamps in seconds, milliseconds, microseconds or nanoseconds to dates in UTC and your time zone, and back. -
Cron Expression Generator
Build a cron schedule from simple choices or check one you have, with a plain-English explanation and the next run times.
Website Diagnostics
Check a website’s DNS records, HTTP and security headers, redirects and SSL certificate.
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DNS Lookup
Look up a domain’s DNS records: A, AAAA, CNAME, MX, NS, TXT, SOA, CAA, SRV and DMARC, or the name behind an IP address. -
HTTP Headers Checker
See the status code and every response header a web address returns, hop by hop, with timings and what each header does. -
Security Headers Checker
Check a site’s HTTPS and security headers (HSTS, Content-Security-Policy, X-Frame-Options and more) and its cookies, with advice on each. -
Redirect Checker
Trace every redirect from a web address to its final page: status codes, where each hop goes, loops and slow chains. -
SSL Certificate Checker
Check a server’s SSL/TLS certificate: who issued it, the names it covers, when it expires, the chain and the TLS version in use.
Infrastructure Tools
Plan networks, servers and storage: subnets, file permissions, uptime targets, bandwidth, RAID and data sizes. Everything runs in your browser.
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Subnet Calculator (IPv4 & IPv6)
Work out the network, broadcast, mask, host range and size of any IPv4 or IPv6 subnet, and split it into smaller ones. -
Chmod Calculator
Convert Linux file permissions between octal (755), symbolic (rwxr-xr-x) and chmod’s u=,g=,o= form, with special bits explained. -
Uptime & SLA Calculator
See how much downtime an availability target allows per day, month and year, turn an outage into a percentage, and combine components. -
Bandwidth & Transfer Time Calculator
Estimate how long a file takes to transfer at a given speed, and convert between monthly traffic and average bandwidth. -
RAID Calculator
Compare usable capacity, fault tolerance and speed for RAID 0, 1, 5, 6, 10, 50 and 60 with any number of disks. -
Data Size Converter
Convert between bytes, KB, MB, GB, TB and KiB, MiB, GiB, TiB, and bits, and see why a 1 TB drive shows as 931 GB.
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