A growing collection of free browser-based tools for developers, network admins, and self-hosters. No signup, no uploads, no tracking — everything runs locally in your browser.
| Server Cost Calculator Compare self-hosting electricity and hardware costs vs managed hosting. |
| Electricity Cost Calculator Daily, monthly, and yearly running cost of any device. |
| Uptime / SLA Calculator Allowed downtime for any SLA percentage. |
| Loan & Mortgage Calculator Monthly payment and full amortization schedule. |
| Tip Calculator Bill split with tip presets and per-person totals. |
| Percentage Calculator Five common percentage modes in one place. |
| BMI Calculator Body Mass Index in metric or imperial. |
| Hosting Comparison Honest reviews of 6 game server hosting providers. |
| Unix Timestamp / Epoch Converter Convert between epoch timestamps and human dates. |
| Date Difference Calculator Days, weeks, months, or business days between dates. |
| Age Calculator Years, months, days, and zodiac from a birthdate. |
| Timezone Converter Convert times across IANA time zones with live clocks. |
| Subnet Calculator IPv4 CIDR with network, broadcast, host range, masks. |
| DNS Lookup Query A, AAAA, MX, TXT, NS, SOA via Cloudflare DoH. |
| IP Address Lookup Public IP plus geolocation and ISP for any address. |
| JSON Formatter & Validator Format, minify, and validate JSON with syntax highlighting. |
| Base64 Encoder/Decoder Encode and decode text or files to Base64. UTF-8 safe. |
| Hash Generator MD5, SHA-1, SHA-256, SHA-512 from text or files. |
| URL Encoder/Decoder Percent-encode URLs and query string components. |
| Regex Tester Live regex testing with highlighted matches and groups. |
| Text Diff Checker Compare two texts line by line. |
| Markdown Preview Live markdown editor with HTML preview. |
| JWT Decoder Decode JSON Web Tokens locally with claim explanations. |
| UUID Generator Generate UUIDs (v1, v4, v7) individually or in bulk. |
| JSON to CSV Convert JSON arrays of objects to CSV with delimiters. |
| CSV to JSON Convert CSV to pretty-printed JSON with RFC 4180 parsing. |
| JSON ↔ YAML Convert between JSON and YAML in either direction. |
| HTML to Markdown Convert HTML to clean Markdown. |
| Schema.org JSON-LD Generator Build structured data for Article, Organization, Product, FAQ, and more. |
| Meta Tag Generator Complete <head> SEO + Open Graph + Twitter Card tags. |
| Robots.txt Validator Validate, test, and generate robots.txt. |
| Nginx → Caddy Converter Convert Nginx config to Caddyfile (best-effort). |
| HTTP Status Codes Reference Searchable reference for all HTTP status codes. |
| Favicon Generator Generate favicon PNGs in every standard size. |
| Image Compressor Compress JPG, PNG, and WebP images locally. |
| Image to Base64 Encode images to data URIs for inline HTML/CSS. |
| Medal Audio Track Splitter Split multi-track audio from Medal.tv clips into individual WAV files for DaVinci Resolve and other editors. |
| Color Picker & Converter HEX, RGB, HSL with WCAG contrast checker and palette. |
| Box Shadow Generator Visual CSS box-shadow with multi-shadow stacking. |
| Gradient Generator Linear and radial CSS gradients with live preview. |
| Border Radius Generator Per-corner CSS border-radius with organic shapes. |
| Password Generator Secure random passwords using crypto.getRandomValues. |
| htpasswd Generator Apache htpasswd entries via Web Crypto. |
| Random String Generator Tokens, IDs, and slugs from any character set. |
| QR Code Generator URL, WiFi, vCard, email QR codes. SVG or PNG. |
| Cron Expression Builder Visual cron builder with next run times. |
| Crontab Cheatsheet Common cron patterns and field reference. |
| Text Tools Counter, case converter, cleaner, find & replace, lorem ipsum. |
| Reading Level Checker Flesch-Kincaid and 5 other readability indices. |
| Dice Roller Standard dice notation roller for tabletop and RPG. |