How It Works
CheckYourWeb runs every security check and virus scan directly in your browser using modern Web APIs. Nothing is ever sent to a server — your data stays on your device, always.
Browser Security Checks
We analyze eleven critical aspects of your browser configuration to give you a comprehensive security score.
Identifies your browser type and version, then cross-references it against the latest stable release. Running an outdated browser exposes you to known vulnerabilities that attackers actively exploit.
Verifies that your connection uses HTTPS with a valid TLS certificate. Without encrypted transport, any data you send — passwords, credit cards, messages — can be intercepted by anyone on the same network.
Inspects your browser cookies for missing security flags such as Secure, HttpOnly, and SameSite. Misconfigured cookies are a top vector for session hijacking and cross-site request forgery attacks.
Checks whether your browser sends the Do Not Track (DNT) header and the newer Global Privacy Control (GPC) signal. These headers tell websites you prefer not to be tracked across the web.
Tests whether WebRTC APIs can expose your real IP address even when using a VPN. This common leak can reveal your true location and identity to websites without your knowledge.
Audits browser permissions for your camera, microphone, location, and notifications. Overly permissive settings let websites access sensitive hardware without explicit consent each time.
Evaluates how unique your browser fingerprint is by analyzing canvas, WebGL, audio context, and font enumeration. A unique fingerprint lets trackers identify you even without cookies.
Detects any active service workers registered in your browser. While legitimate for offline apps, rogue service workers can intercept network requests and serve malicious content.
Scans for insecure HTTP resources loaded on HTTPS pages. Mixed content weakens your encrypted connection and can allow attackers to inject malicious scripts or images.
Checks if the page implements a Content Security Policy (CSP). CSP is a powerful defense against XSS and data injection attacks by controlling which resources can be loaded.
Verifies that a strict Referrer Policy is in place to prevent leaking sensitive URL information to third-party sites when navigating away from a page.
Virus Scanning Process
Our multi-layered scanning pipeline analyzes files entirely in your browser — nothing is ever uploaded.
SHA-256 Hash Computation
Your file is hashed locally using the Web Crypto API to produce a unique SHA-256 fingerprint. This hash is computed entirely in your browser — the file never leaves your device.
Known Malware Hash Database
The computed hash is compared against a bundled database of known malware signatures. If a match is found, the file is immediately flagged as malicious with details about the threat.
Magic Byte Verification
The first bytes of the file are inspected to verify the actual file type matches its extension. This catches disguised executables — for example, an .exe renamed to .jpg.
Heuristic Analysis for Scripts
Script files are analyzed for 25+ suspicious patterns like obfuscated code, eval() calls, encoded payloads, registry modifications, and known exploit signatures. This catches novel threats that aren't yet in hash databases.
Entropy Analysis
Shannon entropy is calculated to detect encrypted, packed, or obfuscated content. High-entropy executables are flagged as potentially dangerous, as malware authors often pack payloads to evade signature-based detection.
Verdict Determination
Results from all analysis stages are combined to produce a final verdict. Files are classified as Clean (no threats found), Suspicious (potential risk detected), or Malicious (confirmed threat). File last modified timestamps are also reported.
URL Safety Analysis
Analyze any URL before clicking — our multi-layered checks detect phishing, malware distribution, and social engineering attacks.
Protocol & Encryption Check
Verifies whether the URL uses HTTPS for encrypted communication. HTTP URLs transmit data in plain text and are flagged as dangerous.
Known Malicious Domain Check
The domain is compared against a database of known malicious and phishing domains. A match immediately flags the URL as dangerous.
Structural Analysis
Examines URL structure for red flags: IP-based addresses, excessive subdomains, non-standard ports, deceptive @ symbols, and suspiciously long URLs.
IDN Homograph Detection
Detects internationalized domain names (IDN) containing non-ASCII characters that visually mimic legitimate domains — a common phishing technique.
Phishing Pattern Analysis
Scans for brand-name impersonation in subdomains and credential-harvesting path patterns (login, verify, confirm) commonly used in phishing attacks.
Safety Verdict
All check results are combined with weighted scoring to produce a safety score (0–100) and a final verdict: Safe, Caution, or Dangerous.
Privacy & Security Guarantees
We built CheckYourWeb with a simple principle: your data is yours and yours alone.
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