On-Page SEO — Blog & Content Reference

Concrete limits, rules, and checklists for on-page SEO. All numbers reflect Google's current SERP rendering (2025-2026).

Title Tag

Property	Limit	Notes
Desktop pixel width	580 px (max ~600 px)	Proportional font — W/M wider than i/l
Mobile pixel width	~920 px (smaller font)	More room on mobile
Character guideline	50-60 characters	Covers ~90% of desktop SERPs
Keyword placement	Primary keyword near the beginning	Natural language, no keyword stuffing
Uniqueness	One unique title per page	Never duplicate across pages
Brand	Append brand after separator if space allows	`Primary Keyword — Brand`

Quick check: If your title exceeds 55 characters, verify pixel width with a SERP preview tool.