Hidden Character Cleaner

About Hidden Character Cleaner

Hidden Character Cleaner is a powerful free online tool that helps you detect and remove invisible Unicode characters, zero-width spaces, and hidden formatting characters from text. These characters are often invisible to the human eye but can cause issues with text processing, programming, data imports, and more.

Common hidden characters include zero-width spaces (ZWSP), byte order marks (BOM), right-to-left marks, control characters, and various invisible Unicode characters that can break code, corrupt data, or cause unexpected behavior in applications.

All text processing is done entirely in your browser - your data never leaves your device, making this tool completely safe for sensitive documents and confidential content.

How to Use This Tool

Paste your text into the input area - this can be text from any source (websites, documents, emails, code)
Click "Highlight Hidden Characters" to visualize where hidden characters are located in your text (they will be marked in red)
Select cleaning options: Choose which types of hidden characters you want to remove:
- Zero-width characters (ZWSP, ZWNJ, ZWJ)
- Byte Order Mark (BOM)
- Control characters
- Invisible Unicode characters
- RTL/LTR direction markers
Click "Clean Text" to remove selected hidden characters
View statistics showing how many hidden characters were found and removed
Copy the cleaned text or download it as a text file

What Are Hidden Characters?

Hidden characters are Unicode characters that don't have a visible representation but are present in text. They can cause various problems:

Zero-Width Space (ZWSP - U+200B)

An invisible space character used for line break opportunities. Often accidentally copied from websites or documents. Can break string matching and validation.

Zero-Width Non-Joiner (ZWNJ - U+200C)

Used to prevent ligature formation in certain scripts. Can interfere with text searching and comparison operations.

Zero-Width Joiner (ZWJ - U+200D)

Used to join characters in complex scripts and emoji sequences. May cause issues when text is processed without proper Unicode support.

Byte Order Mark (BOM - U+FEFF)

A special marker used at the beginning of text files to indicate byte order. Can cause parsing errors in many applications and programming languages.

RTL/LTR Marks

Direction markers for right-to-left and left-to-right text rendering. Can interfere with plain text processing and cause display issues.

Control Characters

Non-printable characters (ASCII 0-31) used for text control. Can cause issues in data files, databases, and APIs.

Common Issues Caused by Hidden Characters

Code Breaking: Hidden characters in code can cause syntax errors, failed string matches, and unexpected behavior
Data Import Failures: CSV files and databases may reject data with hidden characters
Search Problems: Text with hidden characters won't match in search operations
Validation Errors: Forms and validators may reject input containing hidden characters
Copy-Paste Issues: Copying text from websites or PDFs often includes hidden formatting characters
API Failures: JSON and XML data with hidden characters can cause parsing errors
Character Count Mismatches: Visible text length differs from actual character count
Email Problems: Hidden characters in email addresses can prevent delivery

Common Use Cases

Software Development: Clean code snippets copied from Stack Overflow, documentation, or forums
Data Processing: Clean CSV files, database imports, and data migrations before processing
Content Management: Remove hidden characters from CMS content, blog posts, and articles
Email Management: Clean email addresses and content that won't work due to hidden characters
Form Validation: Clean user input before validation to prevent false errors
API Development: Sanitize JSON and XML data before sending to APIs
SEO: Clean meta descriptions and content with invisible characters
PDF Extraction: Clean text extracted from PDFs that contains hidden formatting
Translation: Remove hidden characters from translated content
Web Scraping: Clean scraped content before processing or storage

Features

Comprehensive Detection: Detects all common hidden Unicode characters including ZWSP, ZWNJ, ZWJ, BOM, RTL/LTR marks, and control characters
Visual Highlighting: Highlight hidden characters to see exactly where they are in your text
Selective Cleaning: Choose which types of hidden characters to remove with toggleable options
Character Statistics: See detailed counts of total characters, hidden characters found, and removed
Real-time Processing: Instant detection and cleaning
Copy & Download: One-click copying or download cleaned text as .txt file
Completely Private: All processing done in your browser - no data sent to servers
Works Offline: Use after initial page load without internet connection

Privacy & Security

Your privacy and security are paramount. This Hidden Character Cleaner tool processes all text entirely in your web browser using JavaScript.

Zero data transmission - nothing is sent to any server
No logging or tracking of your text content
Works completely offline after initial page load
Safe for confidential documents, source code, and sensitive data
No cookies or storage of your input
Open source - code can be inspected

Perfect for cleaning sensitive information like API keys, passwords, proprietary code, customer data, and confidential documents.

Technical Details

This tool detects and removes the following Unicode characters and ranges:

Zero-Width Characters:

U+200B (Zero Width Space)
U+200C (Zero Width Non-Joiner)
U+200D (Zero Width Joiner)
U+FEFF (Zero Width No-Break Space / BOM)

Direction Markers:

U+200E (Left-to-Right Mark)
U+200F (Right-to-Left Mark)
U+202A to U+202E (Directional formatting)

Control Characters:

U+0000 to U+001F (C0 controls)
U+007F (Delete)
U+0080 to U+009F (C1 controls)

Other Invisible Characters:

U+00AD (Soft Hyphen)
U+034F (Combining Grapheme Joiner)
U+061C (Arabic Letter Mark)
U+115F, U+1160 (Hangul Filler)
U+17B4, U+17B5 (Khmer Vowel Inherent)
U+180E (Mongolian Vowel Separator)

Examples

Example 1: Cleaning Code from Stack Overflow

When you copy code from Stack Overflow, it often includes zero-width spaces:

const hello = "world"; // Contains ZWSP after "const"

After cleaning, the code works properly without syntax errors.

Example 2: Email Address Issues

Email addresses with hidden characters fail validation:

user@example.com // Contains ZWSP after "user"

Cleaning removes the hidden character, making the email address valid.

Example 3: CSV Data Import

CSV files with BOM characters cause import failures in many systems. This tool removes BOM and other hidden characters to ensure successful data imports.

Frequently Asked Questions

What are hidden characters?

Hidden characters are Unicode characters that have no visible representation but exist in text. Common examples include zero-width spaces (ZWSP), byte order marks (BOM), and control characters. These can cause problems with text processing, code execution, data validation, and more.

Why should I remove hidden characters?

Hidden characters should be removed because they can break code syntax, cause data import failures, prevent text from matching in searches, trigger validation errors, and cause unexpected behavior in applications. They're especially problematic when copying text from websites or PDFs.

Is my text data sent to any server?

No, absolutely not. All text processing happens entirely in your web browser using JavaScript. Your data never leaves your device, making this tool completely safe for sensitive documents, source code, API keys, and confidential content.

How do I know if my text has hidden characters?

Use the "Highlight Hidden Characters" button to visually mark where hidden characters appear in your text (shown in red). The statistics panel also shows the count of hidden characters detected. If text behaves unexpectedly or has character count mismatches, it likely contains hidden characters.

What's the difference between ZWSP, ZWNJ, and ZWJ?

Zero-Width Space (ZWSP) allows line breaks without visible space. Zero-Width Non-Joiner (ZWNJ) prevents character joining in complex scripts. Zero-Width Joiner (ZWJ) forces character joining, especially in emoji. All are invisible but serve different formatting purposes.

Will cleaning remove all my spaces?

No, this tool only removes invisible and hidden characters. Normal spaces, line breaks, and tabs are preserved unless you enable the "Normalize whitespace" option, which only removes excessive whitespace while keeping text readable.

Can I use this for cleaning code?

Yes, this tool is excellent for cleaning code copied from Stack Overflow, documentation sites, or other sources that might include hidden characters. It removes problematic characters while preserving code formatting and regular spaces.

What is a Byte Order Mark (BOM)?

BOM (U+FEFF) is a special character placed at the beginning of text files to indicate byte order encoding. While useful for some applications, BOM often causes parsing errors in programming languages, APIs, and web applications, so it's frequently removed.

Why do websites add hidden characters?

Websites use hidden characters for proper text rendering, line breaking, and internationalization support. However, when you copy text from websites, these formatting characters come along and can cause issues when pasted into code editors, forms, or databases.

Can this tool damage my text?

No, this tool only removes invisible characters while preserving all visible content. However, if your text intentionally uses zero-width characters (like for certain emoji sequences or complex scripts), those will be removed. Always keep a backup if unsure.

How do hidden characters get into my text?

Hidden characters typically enter text through copy-pasting from websites, PDFs, Microsoft Word documents, or rich text editors. They can also appear in files saved with certain encodings, or when text is processed by translation tools or content management systems.

Do I need to clean text every time I copy from a website?

Not always, but it's recommended for critical use cases like code, email addresses, API requests, data imports, or form submissions. For casual text, hidden characters usually don't cause issues. When in doubt, run a quick check with this tool.