Everything in the catalog

Front end for the Jina Reader API that turns a URL into Markdown or text, with an optional Claude summary step.

Compares two JSON documents and highlights added, removed and changed values with character-level detail for strings.

Define properties and nested objects in a form and copy the JSON Schema it generates.

Converts JSON to YAML in block, flow and quoted-string styles side by side.

Type or load LaTeX and see it typeset beside the editor, either as a single MathJax equation or a whole document.

A full-screen countdown timer with large digits and an optional warning threshold.

Lists unique links, with titles, from pasted web content and exports them as plain text, Markdown or HTML.

Highlights phrases and sentence patterns often seen in LLM-written prose, based on a catalogue of known tells.

Animates a world map between the Mercator and Equal Earth projections to show how each one distorts area and shape.

Live Markdown preview from pasted text, a raw URL or a Gist, with tables, code blocks and inline SVG shown as tabs.

Sends Markdown to GitHub's rendering API, shows a live preview and lets you copy the HTML or rich text.

Renders Markdown containing LaTeX equations with KaTeX, showing the HTML output too.

Shows when web APIs first shipped in each browser, using MDN's compatibility data.

Breaks a millisecond count into seconds, minutes, hours, days and weeks, plus a plain-English duration.

Animated bar chart of Elo ratings over time that you can feed with your own JSON.

Reads an MP3 file's ID3 tags, cover art and encoding details without uploading it.

Spells out letters and numbers using the NATO phonetic alphabet for clear radio-style reading.

Plays notes on a small keyboard to show that an octave is a 2:1 frequency ratio.

Text editor that turns long pasted text or files into attachments below the draft.

Shows two PDFs page by page with a third panel marking pixel differences in red.

Opens a PDF from a URL with page navigation and zoom, and keeps the current view in the address bar.

Rescales up to four percentages so they total 100 after you tick off the ones to ignore.

Arranges photos on A4 pages in a grid you configure, in portrait or landscape, ready to print.

Turns PHP serialized strings into readable JSON.