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Developer ToolsZero-Width Character Detector
Detect and remove invisible zero-width characters (ZWJ, ZWNJ, ZWS) that cause formatting issues
0 characters
What are zero-width characters?
Zero-width characters are invisible Unicode characters that don't display visually but can cause formatting issues, security problems, and parsing errors. This tool detects 22 different types including:
- Zero Width Space (U+200B)
- Zero Width Joiner (U+200D)
- Zero Width Non-Joiner (U+200C)
- Byte Order Mark / BOM (U+FEFF)
- Directional formatting marks
- And 17 more invisible characters
Zero-Width Character Reference
| Code Point | Character Name | Description |
|---|---|---|
| U+200B | Zero Width Space (ZWSP) | Used for line breaking opportunities in long words |
| U+200C | Zero Width Non-Joiner (ZWNJ) | Prevents joining of adjacent characters in some scripts |
| U+200D | Zero Width Joiner (ZWJ) | Forces joining of adjacent characters (e.g., emoji combinations) |
| U+FEFF | Zero Width No-Break Space (BOM) | Byte Order Mark, often used at start of files |
| U+200E | Left-to-Right Mark | Forces left-to-right text direction |
| U+200F | Right-to-Left Mark | Forces right-to-left text direction |
| U+202A | Left-to-Right Embedding | Treats following text as left-to-right |
| U+202B | Right-to-Left Embedding | Treats following text as right-to-left |
| U+202C | Pop Directional Formatting | Terminates directional formatting |
| U+202D | Left-to-Right Override | Forces left-to-right direction override |
| U+202E | Right-to-Left Override | Forces right-to-left direction override |
| U+2060 | Word Joiner | Prevents line breaks between characters |
| U+2061 | Function Application | Mathematical function application |
| U+2062 | Invisible Times | Mathematical multiplication |
| U+2063 | Invisible Separator | Mathematical separator |
| U+2064 | Invisible Plus | Mathematical addition |
| U+206A | Inhibit Symmetric Swapping | Inhibits mirroring of symmetric characters |
| U+206B | Activate Symmetric Swapping | Activates mirroring of symmetric characters |
| U+206C | Inhibit Arabic Form Shaping | Prevents Arabic letter shaping |
| U+206D | Activate Arabic Form Shaping | Activates Arabic letter shaping |
| U+206E | National Digit Shapes | Activates national digit shapes |
| U+206F | Nominal Digit Shapes | Activates nominal (European) digit shapes |
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About This Tool
How It Works
- Automatically scans text for invisible zero-width characters
- Detects 22 different types of zero-width and invisible Unicode characters
- Shows exact positions and counts for each character type
- Visualizes invisible characters with visible markers
- Removes all zero-width characters with one click
Common Use Cases
- Debugging text formatting issues caused by hidden characters
- Cleaning text copied from websites and documents
- Detecting hidden tracking or watermarking in text
- Identifying security risks from invisible characters
- Preparing text for databases and strict parsers
Frequently Asked Questions
What are zero-width characters and why are they problematic?
Zero-width characters are invisible Unicode characters that don't display visually but take up space in text. They can cause formatting issues, break text parsing, create security vulnerabilities, interfere with searches, and make debugging difficult. Common examples include Zero Width Space (U+200B), Zero Width Joiner (U+200D), and Byte Order Mark (U+FEFF).
How many types of zero-width characters does this tool detect?
This tool detects 22 different types of invisible and zero-width Unicode characters, including zero-width spaces, joiners, non-joiners, directional formatting marks, mathematical operators, and other special invisible characters that can cause text processing issues.
How do zero-width characters end up in my text?
Zero-width characters can come from copying text from websites, word processors, PDFs, or other formatted sources. They may also be intentionally inserted for text tracking, watermarking, or malicious purposes. Some applications use them for legitimate formatting purposes in complex scripts.
Can zero-width characters be a security risk?
Yes, zero-width characters can pose security risks. They can be used to create deceptive URLs, bypass filters and validation, hide malicious code, create visually identical but technically different strings, and track text distribution. This tool helps identify these potential security issues.
Will removing zero-width characters break my text formatting?
In most cases, removing zero-width characters improves text quality without breaking formatting. However, some languages (like Arabic, Thai, or emoji combinations) legitimately use characters like ZWJ and ZWNJ for proper display. Always review the results before using cleaned text in such contexts.
What is the difference between visualized and cleaned text?
Visualized text shows zero-width characters as visible markers (like [U+200B]) so you can see where they occur. Cleaned text has all zero-width characters completely removed. Toggle between views to understand what's being removed before applying changes.
How can I identify which zero-width character is causing my problem?
The tool displays a detailed table showing each detected character type, its Unicode code point, count, and exact positions in your text. This helps you understand which specific characters are present and where they're located for targeted debugging.
What does the position information tell me?
Position numbers indicate the character index where each zero-width character appears in your text (starting from 0). If there are many occurrences, the tool shows the first 5 positions and indicates how many more exist. This helps locate problem areas in large texts.
Can I use this tool to clean text before database insertion?
Absolutely! This is one of the primary use cases. Zero-width characters can cause unexpected behavior in databases, break unique constraints, interfere with searches, and create data quality issues. Clean your text with this tool before inserting it into databases or APIs.
What is the Byte Order Mark (BOM) and why does it matter?
The Byte Order Mark (U+FEFF) is an invisible character sometimes added at the beginning of text files to indicate encoding. While sometimes needed, it can cause problems when pasting text, interfere with parsers, and create validation errors. This tool helps identify and remove unwanted BOMs.
How do I know if my text has zero-width characters without using this tool?
Zero-width characters are nearly impossible to detect visually. Signs include: unexpected text length, copy-paste behavior differences, search/replace failures, parsing errors, or word count mismatches. This tool provides definitive detection when you suspect invisible characters.
Can zero-width characters affect SEO or web content?
Yes, zero-width characters in web content can confuse search engines, affect keyword matching, create duplicate content issues, interfere with analytics, and impact accessibility. Cleaning text with this tool ensures your web content is properly indexed and displayed.