Kostenlose Online-Tools für Webentwickler
127 schnelle, datenschutzfreundliche Tools für den Entwickler-Alltag — Formatierer, Konverter, Generatoren und SEO-Checks. Ohne Anmeldung, kostenlos.
Prüft ~70 Punkte zu SEO, Speed, Schema, Social & Sicherheit · durchsucht alle 127 Tools · läuft wo möglich im Browser
Deine Tools
Beliebte Tools
Sortiert nach NutzungBold Text GeneratorLinkedIn, Instagram and X don’t have a bold button — but Unicode does. Type your text and copy 𝗯𝗼𝗹𝗱,…HubSpot Form StylerDesign your HubSpot form with a live preview — inputs, labels, two-column rows, checkboxes, error messages…Regex TesterType a pattern and watch matches highlight live in your test text. Inspect every capture group, try…Diff CheckerPaste an original and a changed version to see added, removed and modified lines side by side — with the…Tailwind Color GeneratorPaste one brand colour and get a balanced 11-step shade scale (50 to 950) built in OKLCH — with contrast…Clamp CalculatorEnter a minimum and maximum size and the viewport range — get a zoom-friendly clamp() value with the maths…JSON FormatiererFüge JSON ein, um es zu formatieren, zu minifizieren oder zu prüfen. Fehler werden mit genauer Zeile und…Base64 Encode / DecodeConvert text to Base64 and back with full UTF-8 support (accents, emoji), switch to URL-safe Base64, or…JWT DecoderPaste a JSON Web Token to inspect its header and payload, check when it expires and verify its signature.…Password Strength CheckerType a password to see how many possible combinations it has, how long it would take to crack, which…Possibility & Combination CalculatorHow many possibilities are there? Enter n items and choose r to get combinations, permutations and both…Random Number GeneratorGenerate random numbers (with or without duplicates), pick winners from a list, shuffle names, split…
Webflow- & Figma-Tools
Alle 8 Webflow-ToolsHTML & CSS to WebflowPaste HTML and its CSS, click Copy to Webflow and paste into the Designer — you get real Div Blocks,…Class Name GeneratorDescribe a section in plain words — “hero with tagline, heading, two buttons and an image on the right” —…Class Name Typo CheckerPaste HTML or enter a URL to audit every class name: catch typos like hero_heding, duplicates spelled…SVG to WebflowPaste an SVG from Figma and copy it to Webflow as real Custom Elements — every <svg>, <path> and <g>…Figma CSS to WebflowTurn Figma’s “Copy as CSS” output into tidy values you can type straight into Webflow’s Style panel —…Markdown to Webflow Rich TextPaste Markdown, check the preview and copy it as formatted rich text — headings, lists, links and bold…HTML to Webflow Rich TextPaste messy HTML — from an old site, WordPress export, Google Docs or Word — and get clean semantic markup…Lottie JSON OptimizerMake Lottie animations load faster in Webflow and on any site by stripping data the player doesn’t need —…
SEO-Tools
Alle 30 SEO-ToolsIndexNow SubmitterTell search engines about new and updated pages instantly. Load your sitemap, create and verify your…SEO Checker & Site AuditPaste a URL to run up to 70 on-page SEO checks in seconds. You get a score, a prioritised list of issues…Meta Tag CheckerSee exactly how Google is likely to display your page: title and description measured in pixels, desktop…Heading CheckerVisualise the heading outline of any page. Find missing or duplicate H1s, skipped levels and empty…Image Alt CheckerAudit every image on a page in one table: alt text status, file size, width/height attributes, format and…Keyword Density CheckerEnter a URL and the keyword it should rank for. See where the keyword appears, how often, which phrases…Open Graph CheckerPreview how your link will look when shared on Facebook, LinkedIn, X and Slack. We flag missing tags, test…Page Speed TestRun Google Lighthouse on any URL for mobile or desktop. See performance, accessibility, best-practices and…
Social-Media-Tools
Alle 4 Social-ToolsSocial Share Link GeneratorBuild “share this” links for 12 networks without plugins or tracking scripts — copy single links, the HTML…WhatsApp Link GeneratorTurn a phone number and a pre-filled message into a wa.me click-to-chat link — with a QR code for print…Social Media Character CounterWrite once and see instantly whether your post fits 14 platform limits — including X’s weighted counting…Bold Text GeneratorLinkedIn, Instagram and X don’t have a bold button — but Unicode does. Type your text and copy 𝗯𝗼𝗹𝗱,…
Automatisierungs- & HubSpot-Tools
Alle 3 Automation-ToolsHubSpot Form StylerDesign your HubSpot form with a live preview — inputs, labels, two-column rows, checkboxes, error messages…Date Format ConverterPaste a date format like DD.MM.YYYY HH:mm and get the equivalent for Make, Zapier, n8n, date-fns, Python…JSON Path FinderPaste a webhook payload or API response, click any value and copy its exact path — for JavaScript,…
JSON- & Daten-Tools
Alle 7 JSON-ToolsJSON FormatiererFüge JSON ein, um es zu formatieren, zu minifizieren oder zu prüfen. Fehler werden mit genauer Zeile und…JSON to YAMLPaste JSON and get clean YAML for Kubernetes manifests, Docker Compose, GitHub Actions or any config file.…YAML to JSONPaste YAML — a Compose file, Kubernetes manifest or CI config — and get formatted JSON. Syntax errors are…JSON to CSVTurn a JSON array into a spreadsheet-ready CSV. Nested objects are flattened into columns like…CSV to JSONPaste CSV or TSV and get a JSON array of objects. Quoted fields, embedded line breaks and…JSON to TypeScriptPaste a JSON sample — an API response, a config — and get ready-to-use TypeScript interfaces with nested…JSON to Markdown TableTurn API responses or LLM-generated JSON arrays into a clean, aligned Markdown table for READMEs, docs and…
Encoder & Decoder
Alle 7 Encoding-ToolsBase64 Encode / DecodeConvert text to Base64 and back with full UTF-8 support (accents, emoji), switch to URL-safe Base64, or…URL Encode / DecodePercent-encode text for safe use in URLs, decode encoded strings back to readable text, and break any URL…JWT DecoderPaste a JSON Web Token to inspect its header and payload, check when it expires and verify its signature.…Hash GeneratorCompute MD5 and SHA hashes of any text or file instantly, create HMAC signatures, and paste an expected…UUID GeneratorCreate cryptographically random UUIDs (v4) or sortable, timestamp-based UUIDs (v7) in bulk, then copy or…Unix Timestamp ConverterSee the current Unix time live, convert any epoch timestamp (seconds, milliseconds, micro- or nanoseconds)…HTML Entity EncoderEscape < > & " so text is safe to show in HTML, convert accents and symbols to named or numeric entities,…
Code-Tools
Alle 12 Code-ToolsHTML FormatterPaste minified or messy markup and get clean, consistently indented HTML — including embedded <style> and…CSS FormatterTurn a minified stylesheet into readable CSS with one property per line and properly nested @media blocks.…JavaScript FormatterUnminify and pretty-print JavaScript, JSON or JSX with your preferred indentation and brace style — or…CSS MinifierPaste a stylesheet to shrink it instantly. You’ll see the original and minified size, the percentage saved…SQL FormatterPaste a query — or a whole migration — and get readable SQL with one clause per line, aligned joins and…Regex TesterType a pattern and watch matches highlight live in your test text. Inspect every capture group, try…Diff CheckerPaste an original and a changed version to see added, removed and modified lines side by side — with the…cURL to CodePaste a curl command — from API docs or “Copy as cURL” in your browser’s DevTools — and get ready-to-run…
CSS- & Design-Tools
Alle 9 CSS-ToolsCSS Gradient GeneratorDesign a gradient visually — drag colour stops, change the angle or type, start from a preset — and copy…Box Shadow GeneratorStack multiple shadow layers, tweak offsets, blur, spread and opacity on a live card, then copy the…Clamp CalculatorEnter a minimum and maximum size and the viewport range — get a zoom-friendly clamp() value with the maths…PX to REM ConverterConvert between pixels, rem and em with your own root font size — or paste a whole stylesheet and convert…SVG to JSX ConverterPaste an SVG from Figma, Illustrator or an icon set and get a ready-to-use React (JSX or TSX) component —…SVG to CSS ConverterPaste an SVG and get a compact, URL-encoded data URI plus ready-made background-image and recolourable…Glassmorphism GeneratorDesign a frosted-glass card with live sliders and copy cross-browser CSS — with the…Tailwind Arbitrary Value GeneratorPaste CSS and get Tailwind’s bracket syntax right the first time — spaces turned into underscores, type…
Farb-Tools
Alle 10 Farben-ToolsHEX to RGBA ConverterPaste a HEX code, drag the opacity slider and copy the exact CSS you need — legacy rgba(), modern rgb( /…CSS Variables to TailwindTurn your :root colour variables into a Tailwind theme in one paste — Tailwind v3 tailwind.config.js or v4…OKLCH Color ConverterExplore the perceptually uniform OKLCH colour space with live sliders, see whether a colour fits in sRGB,…Color Name FinderPaste a HEX code to get its closest human-readable name and clean token names for your CSS, SCSS,…Color MixerPick two colours and a number of steps to get evenly blended transition colours — perfect for gradients,…Tailwind Color GeneratorPaste one brand colour and get a balanced 11-step shade scale (50 to 950) built in OKLCH — with contrast…APCA Contrast CheckerCalculate the APCA lightness contrast (Lc) between text and background, see which uses it’s suitable for,…Color Blindness SimulatorUpload a screenshot or design and see it through eight types of colour vision deficiency side by side — or…
Bild-Tools
Alle 6 Bilder-ToolsImage CompressorShrink photos and graphics by 50–90% without visible quality loss. Batch-compress, convert to WebP or…Image ResizerResize a photo to exact pixel dimensions or a percentage, crop it to fill a social-media size, or fit it…Image to Base64Turn a PNG, JPEG, SVG, WebP or GIF into a Base64 data URI with copy-ready CSS and HTML — or paste a Base64…Favicon GeneratorMake a complete favicon package from a logo, a letter or an emoji: a multi-size favicon.ico, Apple touch…OG Image GeneratorCreate a polished link-preview image for Facebook, LinkedIn, X, Slack and WhatsApp in seconds — pick a…QR Code GeneratorGenerate a QR code for a link, Wi-Fi login, contact card, email, phone number or SMS. Customise colours,…
Web- & Netzwerk-Tools
Alle 12 Web-ToolsPing TestMeasure how fast a server responds: enter a host and get the round-trip latency, jitter and failed…Port CheckerTest whether a server accepts connections on specific ports — web (80/443), mail (25/587/993), SSH,…SPF, DKIM & DMARC CheckerFind out why emails land in spam. Enter a domain to check MX, SPF (including the 10-lookup limit), DKIM,…WHOIS LookupEnter a domain to see its registrar, creation and expiry dates, domain age, status codes, nameservers and…DNS Propagation CheckerChanged DNS or moved a site to Webflow? Check whether the new records are visible worldwide — answers from…What Is My IPYour public IP address and everything your browser reveals to the websites you visit — user agent, screen,…User Agent ParserDecode any User-Agent string into browser, engine, operating system and device — and find out whether it…DNS LookupQuery all common DNS record types for a domain in one go, with TTLs, sorted MX records and an SPF/DMARC…
Rechner & Umrechner
Alle 9 Rechner-ToolsPossibility & Combination CalculatorHow many possibilities are there? Enter n items and choose r to get combinations, permutations and both…Random Number GeneratorGenerate random numbers (with or without duplicates), pick winners from a list, shuffle names, split…Age CalculatorEnter a date of birth to get the exact age in years, months and days — plus total days and weeks lived,…Percentage CalculatorSeven everyday percentage calculations on one page. Results update as you type, and each shows the formula…Date Difference CalculatorCount the days between two dates — including business days and a years/months/days breakdown — add or…Time Zone ConverterConvert any time between cities and time zones, see the current time everywhere, and find a meeting slot…Unit ConverterConvert between metric, imperial and technical units in ten categories — with a two-way converter and a…Aspect Ratio CalculatorResize images and videos without distortion: fill in a ratio and one side to get the other, or enter a…
Text-Tools
Alle 10 Text-ToolsSoft Hyphen GeneratorStop long words like “Versicherungsleistungen” from overflowing on mobile: insert invisible soft hyphens…Smart Quotes to Straight QuotesCode copied from Slack, Notion, Word or a blog won’t run? Typographic “smart quotes”, dashes and…Markdown Task List ConverterPaste a plain list, bullet points or half-finished checklist and get clean - [ ] task lists for GitHub,…Password Strength CheckerType a password to see how many possible combinations it has, how long it would take to crack, which…Case ConverterPaste any text and convert it between 11 letter cases — from Title Case for headlines to camelCase and…Word CounterPaste or type your text to count words and characters live — plus reading and speaking time, keyword…Slug GeneratorConvert any title into a clean, lowercase URL slug — with proper transliteration of accents, umlauts and…Lorem Ipsum GeneratorCreate placeholder text for mock-ups and layouts in seconds — classic Lorem Ipsum or readable English…