Invisible Characters Explained
An invisible character is a Unicode character that shows nothing on the screen but is still part of the text. A computer stores it, counts it and copies it like any letter.
There is not one invisible character but many, and they behave differently. This guide sorts them into three types, explains what each was made for, and shows where they help and where they cause trouble.
What is an invisible character?
An invisible character is a character with a Unicode number and no visible shape. A text made only of invisible characters looks empty, but it is not empty.
| Empty field | Field with one invisible character | |
|---|---|---|
| What you see | Nothing | Nothing |
| Number of characters | 0 | 1 |
| Accepted by a form that requires text | No | Often yes |
| Can be copied | No | Yes |
That difference is the whole point. To a person the two fields look the same. To software they are different.
The three types of invisible characters
| Type | Width | Examples | Typical use |
|---|---|---|---|
| Blank characters with width | Like a letter | Hangul filler (U+3164), Braille blank (U+2800) | A blank that takes room |
| Zero-width characters | None | Zero width space (U+200B), zero width joiner (U+200D), word joiner (U+2060) | Control of line breaks and joining |
| Special spaces | Like a space, narrow or wide | No-break space (U+00A0), em space (U+2003) | Spacing in typesetting |
The first type is what people usually mean by "blank text": it is as wide as a letter, so you can see the gap but not the character. The second type takes no room at all. The third type is a real space with a special rule or a special width.
What were invisible characters made for?
None of them was made for blank names or empty messages. Each has a job in writing or typesetting. For four of them, the Unicode rules for line breaking state the job exactly.
| Character | Code | Job |
|---|---|---|
| Zero width space | U+200B | Provides a place where a line may break, without showing a space |
| Word joiner | U+2060 | Prohibits a line break before and after it |
| No-break space | U+00A0 | Separates two words but keeps them on the same line |
| Zero width joiner | U+200D | Joins characters into one, for example the parts of a combined emoji |
| Zero width non-joiner | U+200C | Stops two letters from joining, needed in scripts such as Persian |
| Hangul filler | U+3164 | A placeholder in Korean writing |
| Braille blank | U+2800 | The Braille pattern with no dots |
| Em space | U+2003 | A wide space in typesetting |
The best known of them has its own guide: the zero-width space.
What do people use invisible characters for?
- A field that must not be empty. A form or an app refuses an empty value but accepts a blank character.
- Blank lines and spacing. Some apps remove empty lines from a post or a bio. A line with an invisible character is not empty, so it stays.
- A blank message or name. A message that looks empty, or a name with nothing visible in it.
- Control of line breaks. A zero width space lets a very long word or link break at a chosen place.
- Testing. Developers paste invisible characters into a form to see whether it handles them.
Whether a trick works depends on the app. Many apps remove invisible characters or block them in names, and each app decides this for itself.
What problems do invisible characters cause?
An invisible character that gets into a text by accident, usually through copy and paste, causes errors that are hard to see.
| Where | What goes wrong |
|---|---|
| Passwords and usernames | A pasted value with a hidden character does not match the typed one |
| Search and find | A word with a hidden character inside is not found |
| Links and email addresses | The address looks right and still does not work |
| Code and data files | A line that looks correct fails, or two values that look the same compare as different |
| Character limits | The count is higher than what you see |
The word "hello" with and without a zero width space in the middle looks the same on screen. A computer sees a word of five characters and a word of six. The guide on how to find hidden characters shows how to detect and remove them.
How to see and copy an invisible character
You cannot see an invisible character, but you can count it. Our invisible character tool copies any of eight characters and has a test box that counts the invisible characters in a pasted text.
- Choose one of the eight characters. The tool shows the Unicode code of each.
- Set how many you need, from 1 to 1,000, and press Copy.
- Paste in the Test it here box. The box looks empty, but the count of invisible characters goes up.
We do not test these characters in other apps, so the tool does not promise that a character works in a specific app. If one is removed or refused, try another type from the table above.
Frequently asked questions
- Is an invisible character the same as a space?
- No. A space is one specific character. Invisible characters include special spaces, blank characters with the width of a letter and characters with no width at all.
- How many invisible characters are there?
- Unicode has dozens. Our tool offers eight of the most used ones, and its test box recognises more.
- Does an invisible character count toward a character limit?
- Yes. It is a character like any other, so it is counted even though you cannot see it.
- Are invisible characters safe to use?
- The characters are a normal part of Unicode. They can still cause errors in passwords, links and code, and some apps forbid blank names.
- Why does an app remove my invisible character?
- Many apps trim spaces or block invisible characters, mostly in names. Each app has its own rule.