Don's Tools · Developers · Prompt Cleaner

Prompt cleaner

Paste messy or copied text and get clean plain text for your prompts and datasets. Strip markdown, fix smart quotes, collapse whitespace and remove invisible characters, all in your browser.

What to clean

Prompt Cleaner turns messy or copied text into clean plain text, ready for prompts and datasets. Choose what to apply: strip markdown formatting while keeping the words, collapse repeated spaces and blank lines, straighten curly quotes and long dashes, convert non-breaking spaces and remove the invisible and zero-width characters that often hide in web text. It shows a live character count and how much was removed, and everything runs in your browser with nothing uploaded.

Frequently asked questions

Is my text uploaded or saved?

No. All the cleaning happens in your browser with text replacements. Nothing you paste is sent anywhere or stored.

What does it actually clean?

It can strip markdown formatting, collapse repeated spaces and blank lines, straighten curly quotes and long dashes, and remove invisible or zero-width characters that often sneak in from copied web text. You choose which of these to apply.

Why remove invisible characters?

Copied text frequently contains zero-width spaces, non-breaking spaces and direction marks that you cannot see. They can waste tokens, break matching and cause odd formatting in prompts or datasets, so removing them gives you clean plain text.

Does stripping markdown delete my content?

No, it only removes the formatting marks. Headings keep their words, links keep their text, bold and italic keep the inner text, and lists keep the items, just without the symbols around them.

Is this good for preparing prompts or training data?

Yes. Normalising whitespace, quotes and hidden characters makes prompts and dataset text consistent and predictable, which is exactly what you want before sending it to a model or saving it.