Misc Toolkit
How to use
What it does
A collection of scattered developer helpers you will eventually need: inspect the encoded byte sequence of a character, look up and convert HTML entities, run a small JavaScript snippet in an isolated context, convert CSS units between px, em and rem, test whether a selector actually matches an element, turn data into a Markdown table, build a table of contents from heading levels, query JSON, and check the current viewport size and device pixel ratio.
How to use it
Tabs at the top switch between modules. The encoding viewer displays bytes in UTF-8, UTF-16 and others; the JS sandbox executes snippets and shows the return value; the unit converter links all three units once you set a base font size; selector testing needs both the HTML and the selector pasted in; the Markdown table accepts CSV or TSV; JSON query takes path expressions or dot notation. Output from every module can be copied.
FAQ
Can the JS sandbox test code that manipulates the page DOM?
No. Snippets run in a context isolated from the page and show their return value, which suits pure-logic experiments. Being cut off from the page's DOM and data is a limitation — and also why experiments cannot disturb anything.
What base font size should the CSS converter use?
Your project's root font size, commonly 16px. em and rem reference different things, and only with the correct base are the three-way conversions meaningful — use the results to sanity-check values in your stylesheet.
Can a table copied from Excel be converted to Markdown directly?
Yes. Spreadsheet copies arrive tab-separated by default and the Markdown table module accepts that, CSV as well; paste in, then copy the result straight into your document.
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