Web & SEO

Convert a list of old → new URLs into Apache 301 redirect rules.

Compose a CSS @font-face rule from family, weight, style and sources.

Count anchor text frequencies in pasted HTML.

Searchable list of common ARIA roles, properties and states.

Build a BIMI DNS TXT record pointing to your SVG logo and optional VMC.

Compose CAA DNS records (issue, issuewild, iodef).

Normalise any URL — force https, drop tracking params, sort query.

Good / needs improvement / poor thresholds for LCP, INP, CLS, FCP, TTFB.

Compose a Content-Security-Policy header from common directive sources.

Hash an inline script for use in a CSP script-src directive.

Build simple CSS keyframes and animation shorthand values.

Pick a ratio preset or custom width:height.

Compose CSS border-radius (including squircle-style elliptic radii) with live preview.

Calculate content, padding, border, margin and rendered CSS box sizes.

Compose box-shadow declarations with live preview.

Build a clamp() with min/preferred/max from font and viewport range.

Generate common CSS clip-path shapes with live preview CSS.

Build a CSS color-mix() expression.

Build a CSS conic-gradient — useful for pie charts and dials.

Scaffold a CSS @container query with sensible defaults.

Generate an SVG/CSS duotone filter that maps image shadows and highlights to two colours.

Visually build a CSS filter() rule.

Experiment with flexbox and grid container properties live.

Compose a CSS light-dark() rule with a color-scheme opt-in.

Map physical CSS properties (margin-left) to logical ones (margin-inline-start).

Compose responsive media queries for width, orientation and preference features.

Configure scroll-snap-type / scroll-snap-align.

Generate cross-browser custom scrollbar CSS (standard + WebKit).

Build a CSS text-shadow declaration from offset, blur and colour.

Generate a :root design-token scale (tints, shades, on-colour) from one brand colour.

Visually build a CSS transform shorthand.

Pure-CSS triangle with the classic border-trick.

Convert any CSS unit (px, rem, em, %, vw, ex, ch, pt, pc).

Design a CSS cubic-bezier() easing function with a live preview.

Build a DANE TLSA record (usage, selector, matching, data).

Inspect pasted HTML for favicon, apple touch icon and manifest declarations.

Generate frosted-glass card CSS with backdrop blur and translucency.

Build background-clip CSS that fills heading text with a colour gradient.

Generate hreflang link tags for localized page alternates.

Check whether a Strict-Transport-Security header meets the preload-list criteria.

Generate a table-based, client-safe call-to-action button for HTML email.

Search common HTML entities by symbol, name or numeric code.

Tick the sandbox flags you want and copy the <iframe> tag.

Generate schema.org JSON-LD for Article, Product, FAQ, Organization and more.

Parse JSON-LD and list every @type/@context entity it contains.

Analyse word and phrase frequency in any text.

Generate <img>, <iframe> or <video> with lazy-loading attributes.

Extract every link from pasted HTML or text.

Build a mailto: link with recipients, subject and pre-filled body.

Build a <meta name="robots"> tag from common directives.

Preview how your title and description look in a Google search result.

Generate the MTA-STS DNS TXT record and the policy file body.

Generate <meta property="og:*"> tags with a live Facebook-card preview.

Compose a Permissions-Policy header from feature + allowlist pairs.

Follow up to 10 redirect hops and show the full chain.

Plan and store site-migration redirect maps (301/302/410) per project, synced to your account.

Pick a Referrer-Policy value with a description of what it does.

Build a clean robots.txt from user-agents, allow/disallow rules and sitemaps.

Lint a robots.txt for syntax and directive order issues.

Browse common schema.org types with parent and one-line description.

Parse HTML to audit title, description, canonical, OG, headings and image alt coverage.

Scaffold an install/activate/fetch service worker.

Compose a Set-Cookie header value from name, value, and attributes.

Parse sitemap.xml or sitemap index XML.

Build a sitemap.xml from a list of URLs.

Check a sitemap.xml for namespace, URL count and per-URL field issues.

Generate share URLs for X, Facebook, LinkedIn, Reddit, WhatsApp and more.

Build responsive image markup with srcset and sizes.

Generate static-map image URLs and view links for OpenStreetMap, Google and Mapbox from coordinates.

Build a SMTP TLS Reporting (TLSRPT) DNS TXT record.

Scaffold a Trusted Types policy and the CSP directive that enforces it.

Generate Twitter / X card meta tags with a live preview.

Turn any text into a clean, SEO-friendly URL slug.

Build campaign URLs with source, medium, campaign, term and content parameters.

Build and save UTM-tagged campaign URLs in a reusable, convention-enforcing library.

Compare viewport presets and see which common breakpoints they match.

Generate a basic manifest.json for an installable PWA.

Browse common web-safe font stacks and copy CSS font-family declarations.

Reference for X-Forwarded-For, -Host, -Proto and the RFC 7239 Forwarded header.

Compose an X-Robots-Tag HTTP response header.