Google SERP snippet containers on desktop have a fixed container width of approximately 600 pixels rendered in proportional font (Arial 20px). Proportional fonts assign different pixel widths to letters — for example, uppercase letters like 'W' and 'M' consume up to 18-20px each, while narrow characters like 'l', 'i', and 't' consume only 4-7px. A 55-character title with wide characters can truncate early, whereas a 65-character title with narrow characters may fit perfectly.

Facebook, LinkedIn, and X (Twitter Summary Large Card) recommend an image resolution of 1200 x 630 pixels, representing an aspect ratio of 1.91:1. Keep text, logos, and critical visual elements centered inside a safe 1080x560px zone so cards crop gracefully across varied mobile aspect ratios.

All character calculations, canvas font measurements, Open Graph tag compilation, and image uploads are executed 100% inside your local browser memory using pure JavaScript. No draft titles, client URLs, or uploaded image files are ever uploaded or transmitted to any external server or database.