LLMs don't output plain text. They output Markdown mixed with invisible Unicode control characters — \u200B zero-width spaces, \u00A0 non-breaking spaces, and rich-text clipboard wrappers.

LinkedIn and X parse these unpredictably: double-spacing, raw **asterisks**, and line breaks that collapse into unreadable walls of text on mobile.

Instanets runs a 1-millisecond sanitization pass — entirely inside your browser — that strips every Unicode artifact, removes unsupported Markdown, and normalises all spacing to clean \n characters.

Then it renders your cleaned copy inside a pixel-accurate mobile phone frame, showing exactly where LinkedIn's "See More..." truncation cuts your hook before you publish.