Developer Tools
Format and validate JSON, convert XML to JSON, encode or decode Base64, test regex, convert Unix timestamps, diff two blocks of text, and parse cron expressions — all today, in your browser.
Showing 20 of 85 tools
AI Token Counter
Count exact tokens for GPT-4o, GPT-4, and GPT-3.5 using OpenAI's real tokenizer, compare against Claude and Gemini's context windows, visualize where each token boundary falls, and estimate API cost with your own current pricing.
Try it nowBase64 Decoder
Decode Base64 back to text, with automatic detection of images (shown as a live preview) and JSON (flagged for pretty-printing) — correctly handling UTF-8 unlike plain atob().
Try it nowBase64 Encoder
Encode text or an entire file to Base64 — correctly handling Unicode and emoji (unlike plain btoa()), with a URL-safe variant and instant data URIs for files.
Try it nowBorder Radius & Clip Path Generator
Shape elements two ways: fine-tune each corner's border-radius independently, or apply one of 12 clip-path shape presets — triangle, hexagon, star, arrow, message bubble, and more — with a live preview and copy-ready CSS.
Try it nowCase Converter
Convert text into 14 case formats simultaneously — UPPERCASE, Title Case, camelCase, snake_case, kebab-case, and more — each with its own instant copy button.
Try it nowCron Expression Generator & Parser
Paste any cron expression to get a plain-English description, a field-by-field breakdown, and the next 8 upcoming run times in your local timezone — or start from a quick preset like "every 5 minutes" or "weekdays at 9am" and build one from scratch.
Try it nowCSS Box Shadow Generator
Build single or layered CSS box shadows — offset, blur, spread, color, and opacity per shadow, plus inset support and curated presets — with a live preview and instant copy-ready CSS, entirely in your browser.
Try it nowCSS Gradient Generator
Design linear, radial, and conic CSS gradients with up to 6 color stops, curated presets, and a live preview — copy the exact background CSS with one click, no signup and nothing sent to a server.
Try it nowHTTP Security Headers Analyzer
Fetch a URL's response headers and grade them against the OWASP Secure Headers baseline — CSP, HSTS, X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy, and the Cross-Origin-* isolation headers — with a letter grade and a plain-English reason behind every point.
Try it nowJSON Formatter
Format, minify, or explore JSON as a collapsible tree, with alphabetical key sorting, precise error locations, and a bonus TypeScript interface generator — all in your browser.
Try it nowJSON Validator
Check whether JSON is valid with an exact line and column for any error and a plain-English explanation of the likely cause, plus optional validation against a JSON Schema.
Try it nowQR Code Generator
Generate scannable QR codes for URLs, WhatsApp, Google Reviews, contact cards, calendar events, location, email, phone, SMS, Wi-Fi logins, or plain text — with a center logo, solid or gradient colors, and PNG, SVG, or PDF download, encoded from scratch entirely in your browser.
Try it nowRegex Tester
Test regular expressions with live match highlighting, full capture-group breakdowns (numbered and named), a live replace-mode preview, and a library of ready-made common patterns.
Try it nowSlug Generator
Convert titles into clean, URL-safe slugs with accent handling, stop-word removal, and length control — plus a batch mode that slugifies an entire list at once and exports it as a CSV.
Try it nowSSL/TLS Configuration Checker
Connect live to a domain on port 443 to see which TLS protocol versions it accepts, the negotiated cipher, and full certificate details — issuer, expiry, trust status, and every domain it covers — from a real handshake, not a static lookup.
Try it nowSubresource Integrity (SRI) Hash Generator
Drop in a local JS or CSS file to get its sha256, sha384, and sha512 Subresource Integrity hashes, plus a ready-to-paste <script> or <link> tag — or fetch one from a URL if you don't have the file locally.
Try it nowText Diff Checker
Compare two blocks of text and see exactly what changed, line by line or word by word, using a real longest-common-subsequence diff algorithm — with options to ignore case or whitespace, live stats, and a one-click copyable unified diff.
Try it nowUnix Timestamp Converter
Convert a Unix timestamp to a readable date, or a date back to a timestamp, with ISO 8601, RFC 2822, and SQL formats shown simultaneously, live timezone conversion, and a batch mode for converting a whole list of timestamps at once.
Try it nowUTM & Campaign URL Builder
Builds tagged campaign URLs with all five standard UTM parameters plus GA4's extended fields, warns about the mistakes that actually fragment analytics reports (missing fields, stray spaces, inconsistent casing), generates every channel's link at once in bulk, and remembers your campaign history locally — with no lead-capture form, unlike most free UTM tools.
Try it nowXML to JSON
Convert XML to clean, readable JSON using the browser's real XML parser, with correct attribute handling, clear parse-error messages, and an option to strip namespace prefixes.
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