Requirements for SEO meta tags
Meta tags are machine-readable hints in the head of a page that guide search engines, control snippets, and shape link previews. Getting them right improves crawl efficiency, SERP appearance, and sharing. This guide distills practical requirements and examples.
What actually counts as a “meta tag”
In HTML, meta tags are elements like <meta name="description"> or <meta name="robots">. Closely related, but not meta tags, are <title>, <link rel="canonical">, and hreflang links. They live together in <head> and are covered here when they affect SEO outcomes.
Core meta requirements
1) Meta description
- Purpose: Candidate text for the search snippet; does not influence ranking directly.
- Format: One per page, unique, placed in <head>.
- Length: Aim for 150–160 characters (or ~920px width); write for intent and clarity.
- Content: Include primary topic/keyword naturally, value proposition, and a soft CTA.
- Avoid: Duplicates, boilerplate across many pages, clickbait, and excessive symbols.
<meta name="description" content="Compare cloud backup providers, pricing, and restore speeds. See our expert picks and choose the best plan for your business.">
2) Robots directives
- Global: Use name="robots" for all crawlers; use name="googlebot" or "bingbot" to target a specific bot.
- Placement: In <head> only; the most restrictive directive wins if multiple are present (including HTTP X‑Robots‑Tag).
- Common directives: index | noindex, follow | nofollow, noarchive, nosnippet, max-snippet:[-1|N], max-image-preview:[none|standard|large], max-video-preview:[-1|N], notranslate, noimageindex.
<meta name="robots" content="index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1">
<meta name="googlebot" content="index, follow">
Conflicts: noindex overrides canonical; nofollow can block link graph signals from the page; use sparingly.
3) Viewport (mobile friendliness)
- Required for mobile-first indexing parity and a usable snippet on phones.
- Use width=device-width and an initial scale of 1.
<meta name="viewport" content="width=device-width, initial-scale=1">
4) Charset
- Declare UTF‑8 high in <head> so crawlers and browsers parse characters and emojis correctly.
<meta charset="UTF-8">
Extended meta for rich sharing
While not ranking factors, social meta tags control previews and boost CTR when your links circulate.
Open Graph
- Minimum: og:title, og:description, og:image, og:type.
- Image: 1200×630px (min 600px width), ≤5 MB, descriptive og:image:alt.
<meta property="og:type" content="article">
<meta property="og:title" content="Cloud Backup: 2025 Buyer’s Guide">
<meta property="og:description" content="Independent tests of restore speed, security, and price across 12 providers.">
<meta property="og:image" content="https://example.com/images/backup-guide-1200x630.jpg">
<meta property="og:image:alt" content="Comparison chart of cloud backup services">
Twitter Cards
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:title" content="Cloud Backup: 2025 Buyer’s Guide">
<meta name="twitter:description" content="Independent tests of restore speed, security, and price across 12 providers.">
<meta name="twitter:image" content="https://example.com/images/backup-guide-1200x630.jpg">
Related (not meta) but critical
- Title: Unique, descriptive, ~50–60 characters or ~580–600px, primary keyword early, brand at end.
- Canonical: Absolute URL, one per page, self-referential by default; do not pair canonical with noindex.
- Hreflang: For language/region alternates; always include a self and return links; pair with canonical per locale.
<title>Cloud Backup Providers: Compare Prices and Speeds | Brand</title>
<link rel="canonical" href="https://example.com/cloud-backup">
<link rel="alternate" href="https://example.com/es/copias" hreflang="es">
<link rel="alternate" href="https://example.com/en/backup" hreflang="en">
<link rel="alternate" href="https://example.com/en/backup" hreflang="x-default">
Technical requirements and pitfalls
- Uniqueness: description, title, canonical must be unique per URL.
- One of each: avoid duplicate meta description or robots tags; browsers honor the first, but crawlers may merge with most restrictive rules.
- Order: Place charset and viewport near the top; put robots before scripts that might block rendering.
- Size: Keep critical head markup compact; Google processes up to ~15 MB of HTML, but earlier tags are safer.
- Rendering: If the head is built client-side, render it server-side or via dynamic rendering; crawlers may not see late mutations.
- Pagination: For series, write specific descriptions and note rel="next/prev" is deprecated; rely on strong linking and canonicalization.
- Noindex: Use only when you truly want exclusion; do not block with robots.txt if you expect Google to see the noindex.
- International sites: Do not rely on meta http‑equiv content-language; use hreflang instead.
- A/B testing: Ensure experiments do not output conflicting robots or canonical tags.
Quick checklist
- One unique meta description per indexable page, 150–160 chars, matches search intent.
- Robots set to index, follow by default; strict directives only when necessary.
- Viewport and UTF‑8 present and early.
- OG/Twitter tags filled with high-quality image and consistent title/description.
- Title, canonical, hreflang clean and consistent across variants.
- No contradictory signals (noindex vs canonical; multiple canonicals; mixed follow/nofollow).
Minimal example
<meta charset="UTF-8">
<title>Best Cloud Backup for Small Business | Brand</title>
<meta name="description" content="Find reliable cloud backup with fast restores and strong encryption. Compare providers and pick the right plan for your small business.">
<meta name="robots" content="index, follow, max-image-preview:large">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="canonical" href="https://example.com/best-cloud-backup">
<meta property="og:type" content="article">
<meta property="og:title" content="Best Cloud Backup for Small Business">
<meta property="og:description" content="Find reliable cloud backup with fast restores and strong encryption. Compare providers.">
<meta property="og:image" content="https://example.com/backup-1200x630.jpg">
<meta name="twitter:card" content="summary_large_image">