Präzise Bildschirmmessung, für alle entwickelt.

Unsere Mission

Präzises Online-Lineal wurde aus einer einfachen Beobachtung heraus gegründet: Wenn Sie etwas Physisches messen müssen und kein Lineal in der Nähe ist, sollte Ihr Smartphone oder Laptop die nächstbeste Lösung sein. Yet most browser-based measurement tools rely on rough estimates, fixed assumptions about screen size, or camera-based approaches that introduce lens distortion and perspective errors.

Wir haben uns zum Ziel gesetzt, das genaueste Online-Lineal zu bauen — eines, das Ihr tatsächliches physisches Pixelraster verwendet, mehrere Kalibrierungsmethoden unterstützt und gestochen scharfe, subpixelgenaue Striche bei jeder Zoomstufe darstellt. The result is a free tool that works on any device, in any browser, without plugins or installations.

Präzisionstechnik

Im Kern unseres Online-Lineal-Werkzeugs steht eine canvas-basierte Rendering-Engine, die jeden Strich, jede Beschriftung und jede Unterteilung direkt auf eine HTML5-Canvas zeichnet. Dieser Ansatz gibt uns die volle Kontrolle über jedes Pixel. — no CSS rounding errors, no sub-pixel blurring, and consistent results across operating systems and browser engines.

Our accurate online ruler supports three independent calibration methods:

• Auto-Detect Device — matches your screen from 130+ known device profiles (iPhone, Samsung Galaxy, Google Pixel, MacBook, Surface, and more) for instant, factory-precise calibration.
• Screen Diagonal — enter your display's diagonal size for a custom PPI calculation based on your screen's native resolution.
• Credit Card Calibration — place any ISO/IEC 7810 ID-1 card on the on-screen guide and adjust until it matches, achieving ±0.5% accuracy.

Once calibrated, the ruler displays at actual scale — a 10 cm line on screen equals exactly 10 cm in the real world. All unit modes maintain this precision, instantly switching without losing calibration.

Why Screen-Based Measurement?

Tools that rely on camera input face fundamental challenges: lens distortion, variable focal length, inconsistent lighting, and parallax error all degrade accuracy. A screen-based approach avoids these problems entirely because your display has fixed physical dimensions and a known pixel grid. By accurately measuring PPI (pixels per inch), the tool renders marks that correspond directly to real-world lengths.

This makes screen-based rulers inherently more reliable than camera-based alternatives. No permission prompts, no camera initialization, no calibration patterns to print — just open the page and start measuring in seconds.

Benutzerzentriertes Design

Jede Funktion dieses Online-Lineal-Werkzeugs wurde mit realen Nutzungsmustern entwickelt: verschiebbare Messhilfslinien, Sperren und Entsperren, Dunkelmodus, Vollbildmodus, schwebende und randständige Lineale sowie dauerhafte Einstellungen.

• Dark Mode — comfortable viewing in low-light environments with a full dark theme applied to rulers and controls.
• Fullscreen Mode — distraction-free measuring across your entire display.
• Edge Rulers — rulers positioned precisely at screen edges for maximum workspace.
• Persistent Settings — your PPI, unit preference, and dark mode are saved locally so you never need to recalibrate on the same device.

We also designed for mobile — at 768px and below, the interface adapts with sticky rulers, a compact navigation dropdown, larger touch targets, and optimised layout that preserves full functionality on phones.

Unser Versprechen

Präzises Online-Lineal ist und bleibt kostenlos. Kein Konto erforderlich, keine Datenerfassung, keine Werbung, die die Messung beeinträchtigt. Ihre Kalibrierungsdaten bleiben auf Ihrem Gerät im localStorage.

We actively maintain and improve the tool based on user feedback. If your device isn't recognised, a measurement seems off, or you have a suggestion, contact us and we will address it promptly.

Device database last verified: July 2026. Calibration methodology reviewed and consistent with ISO/IEC 7810 payment card standards.