Remove All Whitespace

The tool deletes every whitespace character in the text, not just doubled ones, and puts nothing in their place. That covers:

• ordinary spaces, tabs and line breaks;
• the non-breaking space that word processors and web pages often use between a number and its unit;
• thin and narrow spaces used in typesetting;
• the full-width ideographic space used in Chinese and Japanese text, so 東京　タワー becomes 東京タワー;
• the invisible byte-order mark that sometimes sits at the start of copied files.

One invisible character survives: the zero-width space (U+200B). Unicode doesn't classify it as whitespace, so it stays in the output. If two strings that look identical still don't match after cleaning, that is a likely cause.

The tool is meant for data where spaces are noise, not for prose. Typical cases:

Other good fits are licence keys, tracking numbers, coupon codes and hex colour lists copied from a document, anywhere a stray space makes a form reject the value.

As the phone number shows, only whitespace goes. Brackets, dashes, dots and plus signs stay. If you need digits only, remove the punctuation separately afterwards.

The site has three tools that deal with spaces, and they do quite different things to the same input. Take Hello world on one line and again on the next:

• Remove All Whitespace (this page): Helloworldagain. Every gap is gone, so words merge.
• Remove Line Breaks: Hello world again. Lines are joined and gaps shrink to one space.
• Remove Extra Spaces: doubled spaces are reduced to one but the line break stays, so you still have two lines.

If your text has words in it that should stay readable, one of the other two is almost always the right choice.