Sanitization

⚡ 50 MB Large Text Ready

Homoglyph Security Detector & IDN Punycode Analyzer

Detect look-alike Unicode homoglyphs, zero-width characters, and Internationalized Domain Name (IDN) spoofing attacks in text and URLs.

Input Workspace

Characters: 87Words: 11Lines: 1Size: 87 Bytes

Output Result

Time: 0 msOutput: 0 Bytes

Tool Customization

No customization controls needed for this tool. It transforms text automatically!

100% Client-Side Privacy & Large-Text Ready

Supports text inputs up to 50 MB. Computations execute entirely within your local browser memory with zero server uploads.

Sanitization Guide

About the Homoglyph Security Detector & IDN Punycode Analyzer

Homoglyph attacks (also known as IDN homograph attacks) occur when malicious actors replace standard Latin characters with visually identical characters from other Unicode scripts (such as Cyrillic 'а', Greek 'ο', or invisible zero-width spaces). To human eyes, google.com (with Cyrillic 'о' U+043E) looks completely legitimate, but leads to a malicious phishing server. The Homoglyph Security Detector & IDN Punycode Analyzer inspects text and URLs in real time. It highlights mixed-script anomalies, identifies disguised Unicode code points, detects invisible zero-width characters, and converts IDNs to ASCII Punycode (xn--...) to prevent phishing and spoofing vulnerabilities.

In-Depth Technical Guide

How Homoglyph Security Detector & IDN Punycode AnalyzerWorks & What the Results Mean

Mechanics of Homoglyph & Homograph Attacks

The Unicode standard contains over 149,000 characters spanning dozens of global scripts. Many characters in separate alphabets share identical or indistinguishable visual glyphs:

Cyrillic vs. Latin: Cyrillic small letter 'а' (U+0430) is visually identical to Latin 'a' (U+0061). Similarly, Cyrillic 'о' (U+043E), 'е' (U+0435), 'р' (U+0440), and 'с' (U+0441) mimic Latin o, e, p, c.
Greek vs. Latin: Greek small letter omicron 'ο' (U+03BF) mimics Latin 'o'.
Invisible Zero-Width Characters: Zero-Width Space (U+200B), Zero-Width Non-Joiner (U+200C), and Right-to-Left marks (U+200F) can be injected into passwords, code, or usernames to bypass security filters or cause invisible payload execution.
IDN Punycode Translation: When internationalized domain names contain non-ASCII characters, browsers translate them to Punycode (prefixed with xn--). Our detector decodes and highlights the exact non-Latin code points.

Practical Applications in Security & Code Review

Phishing URL Verification: Inspecting suspicious domain links from phishing emails before clicking.
Trojan Source Code Audits: Detecting invisible bidirectional Unicode overrides (CVE-2021-42574) in open-source pull requests.
User Registration Sanitization: Preventing brand spoofing and impersonation attacks on social networks and SaaS platforms.

Step-by-Step Guide

How to Use Homoglyph Security Detector & IDN Punycode Analyzer

1Paste any suspicious domain name, URL, code snippet, or text into the editor workspace.
2The detector scans every character for mixed-script homoglyphs, non-ASCII imposters, and zero-width characters.
3Review the Security Threat Level badge (Safe vs. Suspicious / High Risk).
4Inspect the Homoglyph Inspector table detailing character index, visual glyph, Unicode code point (e.g. U+0430), script family, and ASCII lookalike.
5Check the Punycode Translation card displaying the raw xn-- domain representation.
6Copy the sanitized ASCII-only text or full security report with one click.

Capabilities

Key Features & Highlights

Comprehensive Unicode homoglyph detector covering Cyrillic, Greek, Hebrew, and Latin lookalikes.
Invisible character detector exposing Zero-Width Spaces (U+200B), ZWJ, ZWNJ, and RTL overrides.
Full IDN Punycode translator (xn--...) for domain security auditing.
Detailed Character-by-Character Inspector with hexadecimal code points and script family classifications.
1-Click 'Sanitize to ASCII' action replacing spoofed homoglyphs with standard Latin characters.
Visual in-text threat highlighting flagging imposter characters in bold warning colors.
Real-time processing with zero latency.
100% in-browser security analysis with complete confidentiality.

Practical Scenarios

Examples & Real-World Use Cases

Detecting a Cyrillic Homoglyph Phishing Domain

Scenario: Analyzing a spoofed login domain using Cyrillic 'о'.

Sample Input:

https://gооgle.com/login (containing Cyrillic U+043E)

Expected Output:

Threat Level: HIGH RISK 🚨 | Detected Homoglyphs: 2x Cyrillic 'о' (U+043E) | Punycode: xn--ggle-p50aa.com

Unmasks a deceptive phishing URL targeting Google users.

Detecting Hidden Zero-Width Characters in Code

Scenario: Scanning a source code snippet for invisible Trojan characters.

Sample Input:

const adminUser = true;

Expected Output:

Detected: 1 Invisible Zero-Width Space (U+200B) at index 11

Alerts developers to hidden invisible characters that alter variable definitions.

Common Questions

Frequently Asked Questions

An IDN homograph attack is a cyberattack where an attacker registers a domain name containing non-Latin characters (like Cyrillic or Greek) that look identical to a legitimate brand (e.g. 'paypal.com' with Cyrillic 'а') to deceive victims into entering credentials.

Explore More

Related Sanitization Tools

Analysis

Online Word Counter & Character Count Tool

Count words, characters, sentences, and paragraphs.

Open Tool

Sanitization

Duplicate Line Remover & Unique Row Extractor

Remove duplicate lines from text lists.

Open Tool

;