Most deep link generators hand you a worse link than the one you had
The standard version of this tool takes a platform and a username and glues them into something like instagram://user?username=name. It looks technical, so it feels like an upgrade. It is not. A custom scheme is a private address that only means something to one app, and a browser asked to open one it does not recognise has nowhere to go. No page, no app store, usually a dialog saying the address is invalid. The plain web link you started with would at least have loaded the website.
That failure is invisible to the person who built the link, because they have the app. It only shows up in the numbers, as a bio link with taps that never become anything.
The https link usually is the deep link now
iOS Universal Links and Android App Links let an app claim its own web addresses. Instagram tells Apple and Google that it handles instagram.com, so when someone taps an instagram.com link on a phone with the app installed, the operating system routes it to the app before a browser ever opens. Same URL, no app, and it loads the website instead.
This is the part worth internalising: the routing already happened, at the operating system level, using the ordinary link. There is nothing to generate. For every platform this tool knows about, the correct answer to "how do I make my link open the app" is that it already does, and swapping in a custom scheme actively removes the fallback that makes it safe.
The three forms, and when each is the right one
The https link. Opens the app when it is installed, the website when it is not. This is what belongs in a bio, a caption, an email, a QR code, or anywhere else a stranger might tap it. It is the only form that cannot dead end.
The custom scheme. Opens the app and nothing else. It is the right choice in exactly one situation: a link inside a context where the app is guaranteed to be present, such as a button in your own native app, or an internal shortcut on a device you control. It is the wrong choice anywhere the public can reach it.
The Android intent. The intent:// spelling is the one genuinely useful generated artifact, because it carries S.browser_fallback_url, a fallback address baked into the link itself. It opens the app if present and loads the page you nominated if not. The catch is that it only means anything in Chrome on Android. On iOS it does nothing at all, and other Android browsers ignore it. Use it as an enhancement for a known Android audience, never as your only link.
The in-app browser is the thing that actually breaks bio links
A link in an Instagram bio is almost never opened in Safari or Chrome. It is opened in Instagram's own browser, a stripped down web view running inside the app. TikTok, Facebook and several others do the same. Those web views are more restrictive than a real browser about handing control to other apps, which makes a custom scheme least likely to work in precisely the place a bio link is most likely to be tapped.
It is worth knowing this even beyond deep linking, because the same web view is why people report being logged out on your site, why some payment flows stumble, and why analytics look different for social traffic than for everything else.
Some schemes cannot be built from a public link at all
This is where generators quietly produce garbage. Several platforms address content internally by a numeric ID that never appears in the public URL.
Facebook's fb:// scheme wants the numeric ID of a person or page, and a vanity address like facebook.com/yourbusiness does not contain one. Instagram's media scheme wants an internal media ID, not the shortcode in an /p/ link. TikTok's profile scheme wants a user ID, not the handle. A generator that emits a scheme for any of these is concatenating the wrong value into the right shape, and the result opens the app to nothing.
This tool refuses in those cases and tells you which ID is missing, rather than returning a link that looks finished.
You cannot detect whether someone has the app
The obvious idea is to try the scheme, wait a moment, and send anyone still on the page to a fallback. It was a common trick and it no longer works reliably. Browsers throttle timers on backgrounded pages, so the check fires late or not at all, and iOS shows a confirmation dialog that pauses everything while the person decides. The usual result is a visible flash of an error, or a redirect that fires after the app already opened, which yanks people back out of it.
Nothing running in a web page can see the list of installed apps, and that is a deliberate privacy boundary rather than a gap. Fallback has to be handled by something that already knows the answer: the operating system, through App Links, or Chrome, through the intent fallback. Both are listed above.
A short version
Put the https link in your bio. Keep the custom scheme for places you control, where the app is certain to be there. Add the Android intent form only if you have a specific reason and a mostly Android audience. If a tool offers you a scheme for a Facebook page or an Instagram post, it is guessing, and the link will not work.