Zero-Width Character Detector
Detect invisible Unicode characters with our free zero-width character detector. Paste any text and instantly find zero-width spaces (ZWSP), zero-width joiners (ZWJ), directional marks (LRM, RLM), BOM, soft hyphens, and more. View results in a detailed table with code points and hex values, or use the visual view to see highlighted characters inline - all processed entirely in your browser with no uploads. No signup required.
Paste or type text below to detect invisible Unicode characters. Our detector finds zero-width spaces, zero-width joiners, directional marks, invisible operators, and formatting characters - all processed locally in your browser with no uploads.
Why Use Our Zero-Width Character Detector?
Instant Detection
Detect zero-width characters as you type or paste. The zero-width character detector scans every code point in real time and identifies ZWSP, ZWNJ, ZWJ, BOM, directional marks, and invisible operators instantly - with no delay or server round-trip.
100% Private Browser Processing
Your text never leaves your device. The zero-width character detector processes everything locally in your browser, guaranteeing complete privacy for sensitive code, documents, and security research.
Comprehensive Coverage
Detects 20+ invisible Unicode characters including zero-width spaces, zero-width joiners, non-joiners, word joiners, BOM, soft hyphens, Mongolian vowel separators, and all Unicode directional formatting characters (LRM, RLM, LRE, RLO, PDF, LRI, RLI, FSI, PDI).
Free & Unlimited
No signup, no subscription, no usage caps. Detect zero-width characters in unlimited text - completely free forever. Toggle categories on or off, switch between table and visual views, all without limits.
Common Use Cases for Zero-Width Character Detection
String Comparison Debugging
Diagnose why two strings that look identical fail equality checks. Zero-width spaces, ZWNJ, and BOM characters are invisible in most editors but break string comparisons, database lookups, and API validations.
Source Code Sanitization
Detect invisible characters in source code that cause linting errors, parser failures, or unexpected behavior. Zero-width characters in identifiers, comments, or strings can break builds and introduce subtle bugs.
Phishing & Spoofing Analysis
Identify right-to-left override (RLO) and directional marks used in homograph attacks. Attackers use U+202E to reverse filename display, making 'evil.exe' appear as 'exe.live' - catch these with our detector.
Content Watermark Detection
Detect zero-width steganography watermarking in documents and web content. Authors and publishers sometimes embed invisible zero-width characters as digital watermarks to track content redistribution.
Multilingual Content QA
Verify bidirectional control characters in Arabic, Hebrew, and mixed-script content. Incorrect LRM, RLM, or directional isolate sequences cause text rendering issues in browsers, e-readers, and mobile apps.
Data Migration Validation
Inspect imported data for invisible characters before processing. Zero-width characters in database fields, CSV exports, and API payloads cause silent data corruption that is extremely hard to trace without a dedicated detector.
Understanding Zero-Width Characters
What Are Zero-Width Characters?
Zero-width characters are Unicode code points that take up no visible space when rendered. Unlike regular spaces (U+0020), which create a visible gap between words, zero-width characters exist in the text stream without any visual representation. Despite being invisible, they affect text processing, string comparison, line breaking, bidi display order, and emoji rendering. Our zero-width character detector makes these invisible characters visible by identifying each one by its code point, name, and hex encoding.
How Our Zero-Width Character Detector Works
- Paste or Upload Text: Add any text, source code, document, or data file into the input panel. The zero-width character detector accepts plain text, code files, CSV, JSON, HTML, and any text-based format.
- Instant Browser-Based Analysis: Every character is scanned locally in your browser against a database of 20+ known zero-width and invisible Unicode characters. Detected characters are listed in a sortable table with code points, hex values, positions, and surrounding context.
- Switch Views & Filter: Use the Table view for detailed analysis or the Visual view to see highlighted markers inline in your text. Toggle individual character categories on or off to focus on specific types.
Zero-Width Characters Detected
- Zero-Width Spaces & Joiners: ZWSP (U+200B), ZWNJ (U+200C), ZWJ (U+200D), Word Joiner (U+2060), BOM (U+FEFF) - the most common invisible characters found in copied text and web content.
- Directional Marks: LRM (U+200E), RLM (U+200F), LRE (U+202A), RLE (U+202B), PDF (U+202C), LRO (U+202D), RLO (U+202E), LRI (U+2066), RLI (U+2067), FSI (U+2068), PDI (U+2069), ALM (U+061C) - used in multilingual text and exploited in spoofing attacks.
- Invisible Operators: Function application (U+2061), invisible times (U+2062), invisible separator (U+2063), invisible plus (U+2064) - used in mathematical and technical formatting.
- Formatting Characters: Soft hyphen (U+00AD), Mongolian vowel separator (U+180E) - invisible formatting marks that affect text layout and hyphenation.
Privacy and Security
The zero-width character detector processes all analysis locally in your web browser using JavaScript. No text, file contents, or session data is transmitted to any server. Your input never leaves your device, making this tool completely private and safe for source code, confidential documents, and security research. Every detection, filter toggle, and view switch happens instantly on your own machine.
Related Tools
JSON to YAML
Convert JSON to YAML format instantly - Free online JSON to YAML converter
XML to YAML
Convert XML to YAML format for configuration migration - Free online XML to YAML converter
CSV to YAML
Convert CSV spreadsheet data to YAML format - Free online CSV to YAML converter
TSV to YAML
Convert TSV tab-separated data to YAML format - Free online TSV to YAML converter
Frequently Asked Questions About Zero-Width Character Detection
A zero-width character is a Unicode code point that takes up no visible space when rendered. Despite being invisible, these characters exist in the text stream and affect text processing, comparison, and display. Common examples include the zero-width space (U+200B), zero-width joiner (U+200D), and directional marks (U+200E, U+200F).
Our zero-width character detector reads every character in your text using JavaScript and checks each code point against a comprehensive database of 20+ invisible Unicode characters. When a match is found, it records the code point, character name, UTF-8 hex encoding, exact position in the text, and surrounding context.
Our zero-width character detector covers all major invisible Unicode characters: zero-width space (U+200B), zero-width non-joiner (U+200C), zero-width joiner (U+200D), left-to-right mark (U+200E), right-to-left mark (U+200F), BOM/ZWNBSP (U+FEFF), word joiner (U+2060), invisible operators, directional isolates, bidirectional overrides, Mongolian vowel separator, soft hyphen, and Arabic letter mark.
Zero-width characters are used in various types of attacks. The right-to-left override (U+202E) can make malicious filenames appear safe by reversing the display order. Zero-width spaces can be used for invisible text injection, steganography, and watermarking content. In homograph attacks, attackers insert invisible characters into domains or identifiers to create visually identical but functionally different strings.
Absolutely. Our zero-width character detector processes everything entirely in your browser using client-side JavaScript. Your text is never uploaded to any server, stored in any database, or shared with third parties. All detection happens locally on your device.
Yes. Use the Character Categories panel to toggle detection of specific categories: Zero-Width characters (ZWSP, ZWNJ, ZWJ, BOM), Directional marks (LRM, RLM, LRE, RLO, etc.), Invisible operators, and Formatting characters. Each category can be shown or hidden independently.
No artificial limits are enforced. Since all processing happens locally in your browser, practical limits depend on your device memory. The tool handles typical documents, source code files, and data exports without issue.
Yes. The tool is 100% free with no signup, no subscription, and no usage caps. Detect zero-width characters in as much text as you need - completely free, forever. All processing happens locally in your browser with no server interaction.
The table view shows each detected character as a row with all technical details: code point, name, category, UTF-8 hex encoding, position index, and surrounding context. The visual view renders your text with detected characters replaced by highlighted markers, making it easier to see where invisible characters appear in context without reading through tabular data.