Everything in the catalog

Renders Markdown as formatted HTML.

Highlights source code syntax in the output.

Counts tokens for GPT, Claude, Gemini and Grok text and shows the token split and costly words.

Shows which browsers and versions a Browserslist query string would target.

Converts between CBOR binary in hex and the diagnostic text notation.

Translates C and C++ declarations such as function pointers into plain English and back.

Plain guidance for picking an open source license for a project, with summaries of common licenses.

Visualises a CIDR block or IP range with its subnets and masks.

Translates source code between more than 60 programming languages; the page says free tools work without signup.

Collection of converters and formatters for JSON, YAML, XML and similar formats.

Generates cron expressions from a visual form.

Edits cron schedule expressions and explains them in plain English.

Explains a cron expression in words and lists the upcoming run times.

Builds CSS clip-path shapes visually and gives the code.

Drag curve handles to design CSS easing functions and preview the motion.

Builds frosted-glass CSS effects with live preview.

Creates pure CSS spinners and loading bars with adjustable style.

Designs toggle switches in pure CSS.

Produces CSS border-trick triangles and arrows.

Draws a railroad diagram of a regex and highlights how it matches your sample text.

Converts Unix timestamps to human dates and back, with code snippets for many languages.

Flashes ESPHome firmware to a board over USB from the browser.

Colours a pasted PostgreSQL EXPLAIN plan to highlight the slowest nodes.

Generates syntactically valid but random IBANs for testing forms.