Invisible Character Detector

When to use?

Use it when copied text behaves oddly in search or code, when an input form errors for no clear reason, or to check whether pasted text contains invisible characters. Useful for finding hidden-character bugs in sites, documents, and source code.

How to use

• Paste the text to check.
• The types, counts, and positions of detected invisible characters are shown.
• If needed, copy the cleaned text for a clean version.

Input Explanation

Paste the text to check as-is. It detects 27 special characters including zero-width space (U+200B), full-width space (U+3000), BOM (U+FEFF), and non-breaking space (NBSP).

Calculation Basis

It checks each character against a list of invisible code points. The cleanup function deletes zero-width characters and replaces special spaces with normal spaces.

Usage Examples

• Check copied text - Check whether text copied from a web page or PDF has hidden characters.
• Find input-error causes - Check for invisible characters when a form or search fails.
• Clean code/data - Find and remove zero-width characters and full-width spaces in source code or CSV.

Examples

• Detect a hidden zero-width space (U+200B) between words
• Find and remove a BOM (U+FEFF) at the start of a file

Cautions

• Counts can vary by how spaces and line breaks are handled.
• All checks run only in the browser; the text is not sent anywhere.

Guides

Problems invisible characters cause

Zero-width spaces and BOM are invisible but disrupt search, comparison, and code execution. Check first when copied text causes unexplained errors.

Cleanup function

It deletes zero-width characters and direction marks, and replaces special spaces like full-width spaces with normal spaces for clean text.

FAQ

What is a zero-width space?

A character displayed with no width (e.g. U+200B); invisible but it affects search, comparison, and code execution.

Which characters does it detect?

Zero-width spaces, zero-width joiners/non-joiners, BOM, full-width spaces, narrow spaces, direction marks, and more — 27 types.

How is cleaned text processed?

It deletes zero-width characters and direction marks, and replaces special spaces with normal spaces for clean text.

Is the entered text sent to a server?

No. All checks run only in the browser and the text is not sent anywhere.

Related Tools

• Whitespace Remover - Remove whitespace in various ways — leading/trailing, duplicate, or per-line.
• Special Character Table - Copy common special characters — math, arrows, currency, punctuation — with one click.
• Character Counter - Count characters with and without spaces, and line count, in real time.
• Byte Counter - Calculate the byte length of text when stored as UTF-8.
• Punctuation & Whitespace Cleaner - Tidy punctuation and whitespace — duplicate spaces, consecutive blank lines, and per-line edges.
• Case Converter - Convert text, variable names, and filenames to UPPER, camelCase, snake_case, kebab-case, and more.