Help Centre

Getting started

Go to the App page

Open favicheck.agen2ic.ai/app. You'll see a single input field and a Check button.

Enter a URL

Paste the full URL of the site you want to check — for example https://example.com. Include the protocol (https:// or http://). If you omit it, the tool prepends https:// automatically.

Click Check

The tool fetches the page, parses its icon declarations, requests each icon file, and also probes /favicon.ico and /apple-touch-icon.png at the site root (the two files browsers request by convention).

Read the results

A table shows each icon's HTTP status, detected format (from binary magic bytes), real pixel dimensions, and whether the format matches what the <link> tag's type attribute claims. Missing files are highlighted. The summary row shows how many icons are declared vs. found vs. missing.

Frequently asked questions

Why is my favicon not showing in Google Search results? >

Google Search displays the favicon next to your site's name in search results. Several things can prevent it from showing:

No declared icon for Google. Google specifically uses the <link rel="icon"> declaration that does not have an apple-touch- prefix. If your only icon declaration is an apple-touch-icon, Google may not find one. Add a general <link rel="icon" type="image/svg+xml" href="/favicon.svg"> or similar.
Icon URL returns a non-2xx status. Use Favicheck to check — if the declared icon path returns 404 or 5xx, Google cannot fetch it.
Google's cache is stale. Google recaches favicons periodically. A recently updated icon can take days to appear. You can ask Google to recrawl via Google Search Console under "Removals" then requesting a re-crawl of your homepage.
Wrong format. Google supports SVG, PNG, JPG, GIF, WebP, and ICO. An unsupported or corrupted format will be ignored.
Smaller than 48×48 px. Google requires the icon to be at least 48×48 px. Favicheck reports real pixel dimensions — check the Dimensions column.

Why isn't my favicon updating after I replaced the file? >

The most common cause is browser cache. Browsers aggressively cache favicons and only re-fetch them when they think the cache is stale or when you clear the cache entirely.

Try the following, in order:

Hard reload — on most browsers: Ctrl+Shift+R (Windows/Linux) or Cmd+Shift+R (Mac).
Clear browser cache for your site specifically, then reload. In Chrome DevTools: open DevTools (F12), right-click the reload button, select "Empty cache and hard reload".
Use a ?v= query parameter on your icon URL. Update the href from href="/favicon.ico" to href="/favicon.ico?v=2" and increment the version on each release. This bypasses the cached URL.
Check with Favicheck to confirm the new file is actually being served from your server (not just showing in your local browser due to caching).

Favicheck requests each icon fresh from your server — if it shows the old file, the problem is on the server side, not the browser cache.

What sizes should my favicon be? >

There is no single "correct" size because different platforms use different icons. The modern approach is:

One SVG favicon via <link rel="icon" type="image/svg+xml" href="/favicon.svg">. This scales to any size and works in modern browsers (Chrome, Firefox, Edge, Safari 16.4+).
A fallback /favicon.ico (32×32 px) for legacy browsers and older operating systems.
An apple-touch-icon (at least 180×180 px) for iOS home-screen bookmarks and Safari pinned tabs.

If you want to declare explicit sizes (e.g. for Chrome's tab strip), you can add multiple <link rel="icon" sizes="... "> entries for 16×16, 32×32, 48×48, and 192×192 px. Use Favicheck to verify each one exists and has the claimed dimensions.

My site shows a blank icon in the browser tab — what's wrong? >

A blank or default globe icon in the browser tab usually means one of these:

No icon declaration exists. The browser has no instructions and falls back to a default icon. Run a Favicheck check — if the "Declared icons" table is empty, your page <head> is missing the <link rel="icon"> tag.
The declared icon returns 404. The path in your href doesn't point to a real file. Favicheck marks missing icons in red.
The root /favicon.ico is missing. Even without a declared icon, browsers request /favicon.ico by convention. If that file is missing and there's no declaration, you get the default icon. Favicheck checks this in the "Undeclared root fallbacks" table.
The file is the wrong format. For example, an image/svg+xml declaration that actually serves a JPEG. Favicheck's "Match" column flags format mismatches.
Cloudflare-hosted site. Sites behind Cloudflare cannot be checked by Favicheck's backend — but the blank icon problem on your users' side may still be a missing file. Check locally or with another tool if you use Cloudflare.

Why does my apple-touch-icon not appear on iOS? >

iOS uses the apple-touch-icon when a user adds your site to their home screen. Common reasons it doesn't appear:

No apple-touch-icon declared. Add <link rel="apple-touch-icon" href="/apple-touch-icon.png"> to your <head>. Safari on iOS looks specifically for this rel value.
Wrong size. Apple recommends 180×180 px for iPhone 6+ and later retina devices. Smaller icons are scaled up and may look blurry. Use Favicheck to verify the real pixel dimensions.
Missing root fallback. iOS also requests /apple-touch-icon.png at the site root by convention, even without a declaration. Favicheck's "Undeclared root fallbacks" table shows this.
Server returns a fallback image. Some servers are configured to return a default image for any missing PNG. Favicheck reports what the server actually serves for that path — if it's a generic 404 page rendered as PNG or a default image, it won't display correctly on iOS.
iOS cache. Like desktop browsers, iOS caches the icon. A full reboot or adding the site to the home screen on first visit (before cache clears) may show the old icon. Force-quit Safari and re-add the bookmark.

How does Favicheck detect file formats? >

Favicheck reads the binary magic bytes (the first few bytes of the file), not the file extension or the HTTP Content-Type header. This means it detects the actual file format regardless of what the server claims.

Supported formats detected by magic bytes:

PNG — 8-byte PNG signature (starts with 89 50 4E 47)
ICO — ICO directory header (starts with 00 00 01 00 or 00 00 02 00)
JPEG — SOI marker (FF D8 FF)
GIF — GIF87a or GIF89a signature
BMP — "BM" header
WebP — "RIFF" + "WEBP" chunk
SVG — XML declaration or <svg tag (detected as format, but pixel dimensions are parsed from viewBox/width/height attributes)

False negatives are possible for corrupt files or exotic encodings. Favicheck reports unknown when the magic bytes don't match any known format.

Known limitations

!! Cloudflare-hosted sites cannot be checked. The tool's backend (Cloudflare Worker) cannot connect to other Cloudflare-hosted domains. Those sites return "cannot connect" regardless of whether an icon exists. If your site is on Cloudflare, check icons locally or via a different network. This is a networking limitation, not a bug.
!! JavaScript-injected icons are invisible to the tool. Favicheck fetches the raw HTML of the page. Icons added by JavaScript after page load (e.g., via a widget, framework, or dynamic theme provider) are not included in the declared-icons report. Only server-rendered <link> tags in the initial HTML are scanned.
!! Server fallback icons. If your server is configured to return a default or fallback icon for any missing path (e.g., an nginx catch-all), Favicheck will report that default as a "found" icon. The tool cannot distinguish between a real icon file and a server-side redirect/fallback. Review your server configuration to interpret the results correctly.
!! No batch checking. Each check accepts one URL at a time. A Pro tier with batch, export, and scheduled monitoring is planned but has not been built yet. See the Pricing page for details.
!! No user accounts or history. Check results are ephemeral. Favicheck has no database, no accounts, and no way to revisit a previous check. Bookmark the page, not the results.
!! No image generation or design advice. Favicheck diagnoses what exists and what is missing. It does not generate icon images, suggest a design, or optimise icon files. For those needs, use a dedicated favicon generator tool.
!! No legal entity. The operator has not yet registered a company or designated a jurisdiction. Terms and privacy policy are provisional. This page will be updated with a contact method and legal information when the operator establishes a company.

Contact us

Support is not yet available by email because no mailbox has been set up and no legal entity has been registered. This is a known gap — see needs.md for the current list of infrastructure requirements.

In the meantime:

Check the FAQ above — most common questions are answered there.
Run a Favicheck check on your site to see exactly what's present and what's missing. The output table tells you more than most support queries can.

This page will be updated when a contact route is available.