About OverlayCheck
The studio-grade, zero-knowledge platform engineering precision image forensics, open-source intelligence (OSINT), CTF steganography tools, and privacy defenses directly inside the browser.
The Zero-Knowledge & Chain of Custody Standard
Traditional forensic and OSINT tools routinely require investigators, journalists, and security researchers to upload sensitive evidence to remote cloud servers. This introduces unacceptable risks: chain-of-custody contamination, third-party data leaks, metadata harvesting, and unverified retention.
OverlayCheck solves this at the architectural layer. Every single byte of image data, every EXIF marker, every bit plane, and every byte of binary payload is processed strictly in your local browser memory using Web Workers, HTML5 Canvas, TypedArrays, and the native Web Crypto API.
100% In-Browser Execution: Zero network uploads. When you inspect an image on OverlayCheck, your network activity tab remains completely silent. Your files never touch our servers or any third-party infrastructure.
Two Specialized Operational Suites (12 Tools)
Engineered for OSINT researchers, investigative journalists, cybersecurity practitioners, and CTF players.
1. Image OSINT & Verification Suite
- EXIF & GPS Scrubber: Lossless JPEG/PNG/WebP/HEIC metadata stripping, satellite coordinate mapping, and camera serial number anonymization.
- Error Level Analysis (ELA): Multi-pass JPEG quantization recompression to expose airbrushed artifacts, fake receipts, and forged documents.
- Steganography Bit Slicer: 8-channel bit-plane decomposition (R, G, B, Alpha) with sequential LSB ASCII string extraction.
- Binary File Carver: Detects EOF delimiters (`FF D9`, `IEND`) to carve concealed ZIP/PDF archives and scan embedded strings.
- Visual Forensics: 2D Sobel luminance directional vectors on an HSV wheel, Laplacian edge detection, and sensor noise residuals.
- Reverse OSINT & Hashes: Cryptographic SHA-256/MD5/SHA-1 and perceptual hashes (pHash, dHash, aHash) with 1-click pivot search links.
2. CTF, Pentesting & Defender Suite
- PNG IHDR & CRC32 Bruteforcer: Auto-recovers cropped height dimensions in CTFs by testing 8,192 permutations in under 30ms.
- Pixel Math & XOR Engine: Solves visual cryptography via dual-image XOR/difference logic and single-byte (0x00–0xFF) key scrubbing.
- Magic Byte Header Fixer: Inspects and repairs wiped or transposed magic signatures across 150+ file formats with an in-browser hex editor.
- Image Security Auditor: Heuristically audits uploads for embedded PHP/ASP web shells, polyglot payloads, and SVG XSS vectors.
- Pixel Flood DoS Auditor: Analyzes decompression bombs without allocating memory, calculating expansion ratios and hardening rules.
- Forensic QR Restorer: Otsu adaptive thresholding, inversion, and morphological scratch repair for degraded barcodes and quishing analysis.
Research, Methodology & Authorship
OverlayCheck pairs each forensic module with comprehensive technical documentation in our Forensic Knowledge Hub. The research guides and technical briefings are authored by Rutvij Khatri, focusing on reproducible investigative methodologies, mathematical explanations (quantization matrices, Sobel filters, discrete cosine transform), and open-source intelligence tradecraft.
Support & Inquiries
Have questions about a specific forensic technique, feature requests, or vulnerability research feedback? Reach our engineering desk directly: