Rawlens — Markdown, JSON & CSV Viewer

Renders raw Markdown, JSON, and CSV opened in the browser as styled documents, with switchable themes.

Open a Markdown, JSON, or CSV file — on the web or on your own disk — and read it as a formatted document instead of raw text. JSON • A collapsible tree with values coloured by type, expand / collapse all. • Works on any JSON response, not just .json files — open an API endpoint in a tab and read it. • Very large numbers (64-bit ids) are shown exactly as written, not rounded. • Invalid JSON shows the error and the raw text, never a blank page. CSV • A sortable table with a sticky header: click a column to sort, numbers sort as numbers. Comma, semicolon, tab, and pipe files all work. • CSV links open in the viewer instead of downloading; files a site marks as downloads still download. Local CSV files open from the toolbar icon. SEARCH • Search inside JSON and CSV with matches highlighted. JSON search finds matches inside collapsed sections — which the browser's own find cannot — and shows each matching record in full. CSV search filters to the matching rows. Every view has a Raw toggle and a Download button. MARKDOWN • Headings, bold/italic, code blocks, blockquotes, nested and task lists, tables with alignment, links, images, and horizontal rules. • YAML frontmatter is shown as a muted block instead of breaking the layout. • Heading anchors work, so #section links land where they should. • Full-width layout that uses your whole window. THEMES Twelve colour themes — light, dark, and warm paper tones — switchable from the toolbar in the corner of the page. Your choice is remembered and applies to every file you open, in every tab. PRIVATE BY CONSTRUCTION • Everything happens on your computer. No server, no account, no analytics, no network requests. • The extension only renders pages that really are raw Markdown, JSON, or CSV. Ordinary web pages are left alone, whatever their address ends in. • The file's own HTML is never executed — it is displayed as text. LOCAL FILES To render files from your own disk, enable "Allow access to file URLs" on the extension's details page. Without it, only files on the web are rendered. Local CSV files open from the toolbar icon (the browser downloads them otherwise).