Tool directory
Preview Tools
Preview text and file-based diagrams online with focused browser workspaces.
Available tools
13Mermaid Preview
Preview Mermaid diagrams online with a live editor, syntax checks, examples, and SVG/PNG export.
PlantUML Preview
Preview PlantUML diagrams from text using a replaceable server renderer.
Markdown Preview
Preview Markdown with Mermaid code block rendering.
SVG Code Preview Editor
Paste SVG markup or a data URI, preview it safely, and export cleaned SVG.
Open Graph Preview Debugger
Preview og:title, og:description, og:image, Twitter cards, and social share snippets.
robots.txt Tester
Test robots.txt Allow and Disallow rules for a target URL.
Sitemap XML Viewer
Preview sitemap XML URLs, sitemap indexes, duplicates, lastmod, and hreflang alternates.
HTML Preview Sandbox
Preview HTML components, email snippets, and landing sections in a script-blocked sandbox.
CSS Gradient Preview
Preview CSS linear, radial, conic, and repeating gradients with extracted color stops.
Base64 Image Preview
Preview Base64 image strings and data URLs with MIME type and size analysis.
CSS Box Shadow Preview
Preview CSS box-shadow values on realistic cards and compare shadow layers.
Color Palette Preview
Preview hex, rgb, hsl, and CSS variable palettes with adjacent contrast checks.
Draw.io Viewer
Open draw.io and diagrams.net XML files online before sharing or converting them.
Priority workflows