UD5 Toolkit
HTML Live Previewer - Online Code to Rendered View
Write or paste HTML, CSS, and JavaScript and instantly see the rendered output in a sandboxed iframe. A handy frontend prototyping tool.
GeoJSON Map Previewer - Online Render on Interactive Map
GeoJSON Map Previewer
Paste or upload GeoJSON to instantly render it on an interactive map.
GeoJSON Input
Click features for details
Frequently Asked Questions
GeoJSON is a lightweight format for encoding geographic data structures. It supports points, lines, polygons, and their multi-part equivalents. It's widely used in web mapping libraries like Leaflet, Mapbox, and OpenLayers.
Yes, this tool renders GeoJSON client-side without size limits beyond browser memory. However, extremely large files (e.g., over 50MB) may slow down rendering. For better performance, simplify your geometries using tools like Mapshaper.
GeoJSON mandates the WGS84 coordinate system (EPSG:4326) with longitude/latitude pairs in decimal degrees. If your data uses a different CRS, convert it before preview.
You can download the GeoJSON file using the Download button and share it. To save the exact map view, take a screenshot. The tool does not store any data on servers.
Absolutely. All processing is done locally in your browser. No data is sent to any server. You can use the tool offline after the page loads.
Tattoo Placement Simulator – Upload a Photo & Test Designs
Upload a photo of your arm, leg, or back and overlay a tattoo design PNG to see how it looks in different positions before committing.
Map Coordinates Finder – Click to Get Latitude & Longitude
Click anywhere on a world map to instantly see its coordinates in decimal degrees and DMS. Copy them for use in GPS or school projects.
Google SERP Snippet Preview – Title, Meta & URL
Enter your page title, meta description, and URL slug to see how they will appear in Google’s search results. Flag truncation and optimize for CTR.
Email Subject Line Tester – Preview & Length Check
Type your email subject line and see how it will appear on mobile and desktop inboxes. Checks character limits and flags spammy words for better open rates.
Simple Dungeon Map Generator – Random D&D Layouts
Generate a random top‑down dungeon map with rooms and corridors for your tabletop RPG session. Regenerate or tweak the seed for new layouts.
QR Code Logo Embedder – Online Preview Before Print
Generate a QR code and overlay your logo in the center. Check if it still scans. Download composition.
Screen Reader Text Preview - Online See Hidden A11y Labels
Enter HTML with aria-labels and see what a screen reader would announce. Simulates common patterns. Local educational tool.
CSS Animation Library Browser - Online Preview & Copy Keyframes
Browse a collection of ready-to-use CSS animations (fade, slide, bounce). Click to preview, then copy @keyframes and class to your project. Local tool.
Social Card Meta Tester - Online See Facebook, Twitter, LinkedIn Previews
Enter a URL and see live mocked previews for Facebook, Twitter, LinkedIn, and Slack based on its meta tags. Find missing tags.
GeoJSON Validator - Online Check Geometry & Properties
Paste a GeoJSON object and validate its structure. Catch missing coordinates, wrong types, and feature errors. Local.
CSV to GeoJSON Converter - Online Map Data Generator
Map CSV columns with latitude/longitude to GeoJSON points. Create map‑ready data instantly. All local.
Twitter Card Previewer - Online See How Tweets Render
Enter a URL and fetch its Twitter card meta tags. See a live preview of how the tweet will appear. Debug social sharing.
HDR Color Preview - Online See Wide Gamut Colors
Test if your display supports HDR colors by rendering a gradient in Rec.2020 space. See what you're missing. Canvas based.
Google Fonts Pairing Suggestions - Online Visual Tester
Select a heading font and see a set of well‑paired body fonts. Live preview with your own text. Copy the import code.
OpenAPI to HTML Preview - Online Swagger UI Generator
Paste an OpenAPI YAML/JSON and render a static, readable API document. No server, pure browser‑based rendering.
SEO Title & Meta Optimizer - Online Pixel Width Preview
See how your page title and description will look in Google SERP. Check pixel width and character count. Local tool.
Local Font Viewer & Preview - Online Test Styles
Browse the fonts installed on your system and type a custom phrase to see how it looks. Uses Local Font Access API where available.
Open Graph Audit Tool - Online Check Social Meta
Enter a URL and see a preview of how it will appear when shared on Facebook, Twitter, LinkedIn. Detect missing tags.
Font Size Scale Preview - Online Typography Visualizer
Type a few words and see them rendered at every heading size (h1–h6) with your chosen font. Perfect for design systems.
CMYK Color Preview - Online See Print vs Screen
Preview how a CMYK value will look on screen (approximate). Compare with its RGB equivalent. Pre‑press check.
Image to Laser Engraving Preview - Online Halftone Stipple
Apply a stipple or halftone effect to preview how an image might look when laser engraved. Download black‑and‑white output.
HTML Includes Previewer - Online Simulate SSI Includes
Paste multiple HTML snippets (header, footer) and a main content, then combine them into a single preview. Static site helper.
Quilt Pattern Previewer - Online Fabric Layout Visualizer
Arrange virtual fabric squares or triangles on a grid to preview a quilt pattern. Change colors and sizes. Export layout.
Swagger/OpenAPI YAML Previewer - Online Render & Test
Paste your Swagger/OpenAPI YAML and see a rendered API documentation preview with expandable endpoints. All local rendering.
Open Graph Debugger - Online Fetch & Preview Social Card
Enter a URL to see exactly what Open Graph and Twitter card tags will be shown when shared on social media. Fetch from browser.
Recent Earthquake Tracker - Online USGS Live Data Map
View recent earthquakes worldwide on a map. Fetches public USGS GeoJSON feed directly from browser. Real-time data.
Lottie Animation Previewer - Online JSON Player
Paste Lottie JSON code or upload a .json file and see the animation play. Control speed and loop. Perfect for developers.
Random Dungeon Map Generator - Online RPG Floor Plan
Generate random dungeon maps with rooms and corridors. Use for tabletop RPGs. Every layout is unique. Export as image.