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Text Sanitizer

Clean text by removing invisible characters and normalizing format.

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What Are Unicode Control Characters?

Many Unicode characters are designed to control the interpretation or display of text without having any visual or spatial representation. The C0 control codes (U+0000 to U+001F) originate from the ASCII standard and include characters such as NULL, TAB (horizontal tabulation), LF (line feed), and CR (carriage return). Additionally, Unicode introduces zero-width characters like the zero-width space (U+200B), zero-width non-joiner (U+200C), and zero-width joiner (U+200D), as well as bidirectional text control marks.

These characters often sneak into text when copying and pasting from web pages, word processors, or PDF files, causing issues in string comparison, search, form validation, and automated data processing. C1 control codes (U+0080 to U+009F) inherited from ISO/IEC 8859-1 also exist.

Frequently Asked Questions

What are invisible Unicode characters?
These are codes with no visual representation that affect text interpretation. They include C0 control codes (U+0000-U+001F) like NULL, TAB, LF, and CR; C1 codes (U+0080-U+009F); and zero-width characters like U+200B. They sneak in when copying from web pages, PDFs, or emails, causing string comparison and validation issues.

How to remove invisible characters from text?
Use our online text cleaner: paste the text into the input area and the tool will automatically remove all Unicode control characters, normalize line endings, and convert tabs to spaces. The result is clean text ready for programming, databases, or data processing.

What problems do control characters cause in programming?
They cause string comparison failures (apparently identical strings not matching), form validation errors, failed database searches, JSON/XML parsing issues, and security vulnerabilities such as homoglyph attacks or bidirectional confusion (CVE-2021-42574).

What is a zero-width space (U+200B) and how to remove it?
Zero-width space (U+200B) is an invisible Unicode character that indicates a possible line break without adding visible space. It is frequently introduced when copying text from web editors, CMS, or word processors. Our cleaner automatically detects and removes it along with other zero-width characters.

How to normalize line endings between Windows, Linux, and macOS?
Different OS use different line break characters: Linux/macOS uses LF (U+000A), Windows uses CR+LF, and classic macOS used CR. Our tool automatically unifies all formats to a single standard (LF), ensuring cross-platform compatibility.

Why does my text pasted from a PDF contain strange characters?
When copying from PDFs, processors often insert invisible control characters like zero-width spaces, byte order marks (BOM), and font control characters. Use the text cleaner to normalize your content after extracting it from any PDF or document.

Common Use Cases

  • Clean text pasted from the web: Remove invisible Unicode characters that sneak in when copying text from web pages, PDF documents, or emails.
  • Normalize line endings: Unify different line break formats (LF on Linux/macOS, CR+LF on Windows, CR on classic macOS) to a single standard.
  • Remove zero-width characters: Strip zero-width spaces (U+200B) and other invisible markers that break string comparison and database searches.
  • Debug bidirectional text: Detect and remove directional control characters (LRM, RLM, LRE, RLE) that can alter the expected display of text.

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