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The meta tags that actually matter
Title, meta description, canonical, and Open Graph tags do most of the work in your HTML head. Here are the length rules and conventions Sight checks, with the exact thresholds.
Meta tags are the machine-readable elements in your HTML <head> that tell search engines and social platforms what a page is, how to display it, and which version of it to index. Most of the tags a page could have don't matter much anymore — but four groups still carry real weight: the <title>, the meta description, the canonical link, and the Open Graph tags. Get these right and you've handled the majority of on-page meta hygiene; get them wrong and you leak clicks, split ranking signals, or render broken previews.
This guide covers what each one does and the exact thresholds Sight uses so you can match them.
How long should a title tag be?
The <title> is the single most important on-page tag: it's your page's headline in search results, browser tabs, and often the label an AI answer engine uses when it cites you. Sight's title length check looks for 30 to 60 characters, inclusive. Under 30 usually means you're wasting space — the title is missing descriptive or brand context. Over 60 and it's liable to be truncated with an ellipsis in the search snippet, cutting off your message mid-phrase.
The practical rule: front-load the specific topic or product name, then add brand or category context until you're comfortably inside the band. Measure the rendered title, not just the source — some CMSes append a suffix like | Brand Name at render time that pushes you over 60.
How long should a meta description be?
The meta description doesn't affect ranking directly, but it's the sales copy under your title in the results — a good one lifts click-through. Sight's description length check targets 70 to 160 characters. Shorter than 70 and you're leaving persuasion on the table; longer than 160 and the tail gets truncated, so anything past that first 160 characters may never be seen. Write a full-sentence summary with a reason to click, and keep the key message up front.
What does the canonical tag do?
The canonical link — <link rel="canonical" href="…"> — tells search engines which URL is the authoritative version of a page when the same or similar content is reachable at multiple URLs (with tracking parameters, trailing slashes, or across http/https). Without it, duplicate URLs can split your ranking signals or let the wrong variant get indexed.
Sight checks two things here. The canonical presence check confirms a canonical is declared at all. The self-consistency check is stricter: it flags pages that declare more than one canonical (crawlers may ignore all of them), point the canonical at an invalid URL, or point it at a different host — which effectively tells search engines to de-index the page on your own domain. In the common case, a page's canonical should point at itself.
What Open Graph tags should every page have?
Open Graph tags control how your links look when shared in social apps, chat, and messaging. The essentials are og:title and og:description for the text, and og:image for the preview picture. Sight recommends an og:image of 1200×630 pixels and warns on images below a 200-pixel minimum, and it looks for og:image:width and og:image:height to be declared so platforms can render the preview immediately. It also checks that your twitter:card is a valid type (summary_large_image is the usual choice) and that og:url agrees with your canonical, so share signals don't split across URL variants.
- What's the ideal title and description length in one line?
- Title 30–60 characters, meta description 70–160 characters. Those are the exact ranges Sight scores against.
- Does the meta keywords tag matter?
- No. Major search engines have ignored the meta keywords tag for well over a decade. Don't spend time on it.
- Should every page's canonical point to itself?
- In most cases, yes — a self-referencing canonical is the safe default. Point it elsewhere only when you deliberately want to consolidate duplicate URLs onto one authoritative page, and never point it at a different domain unless you truly intend to de-index the page on yours.
The takeaway
Four things: a unique 30–60 character title, a 70–160 character description that earns the click, a self-referencing canonical, and Open Graph tags with a properly sized image. That's the on-page meta layer handled. From there, structured data and content quality do the deeper work — but these tags are the cheapest, highest-leverage fixes on most sites.
Check your title, description, and canonical tags — run a free scan