The questions, answered first.

Device fingerprinting recognises a returning browser or device from what it reports about itself instead of from a cookie it stores. With Fingerly, an SDK describes the browser or app, the server decides who it is and issues a visitor ID, and the same device gets the same ID on later visits.

A cookie is a file kept in the browser, so clearing it or opening a private window starts over, while a device fingerprint keeps nothing in the browser. Fingerly’s browser SDK writes no cookies and nothing to local storage, and the identifier is remembered on Fingerly’s side.

For recognising a device, yes, because an address changes with the network while the device does not. Fingerly never makes the address part of identity; it uses the address for network signals such as VPN, proxy and Tor, and for a location mismatch.

In part. A CAPTCHA asks every visitor to prove something, while Fingerly reports automation, virtual machines and unusual activity without asking anyone for anything. You can still use a challenge for the sessions Fingerly marks as uncertain.

No. Recognising a device is not proving who is using it. Fingerly is an input to authentication decisions, for example skipping a second factor on a familiar device, and it never replaces a password, a passkey or a second factor.

A device ID is the general idea of an identifier for one device, and a visitor ID is Fingerly’s browser identifier for it. In a native app the equivalent is a random install ID, so treat web and app IDs as separate and join them through your own account records.

Yes, in the ordinary case. A private window resets cookies and storage but not the device, so Fingerly still recognises it, and it can also report the session as incognito. Browsers that randomise what they report are recognised less often.

Yes, with native SDKs. Fingerly’s iOS and Android SDKs, and the React Native, Flutter and Lynx bridges, recognise an app by a random install ID the SDK keeps for it, never by its hardware, and add checks for emulators, root, jailbreak, cloned apps and tampering.

It depends on the browser and the device, and an honest vendor does not publish one percentage for it. Fingerly returns a visitor confidence on every response and marks reports too thin to identify anyone as not identifiable, rather than guessing.

Parts of it can, which is why Fingerly does not trust what a client says about itself. Spoofing leaves contradictions that Fingerly reports as tampering or an anti-detect browser, and the decision is made on the server. No detection is unbeatable, so treat it as one input.

In the browser, Fingerly’s identify call answers after an initial collection budget of 300 milliseconds. Slower work continues separately afterwards and never changes the identification, the score or the charge.

It depends on what you need, so compare on four points: whether identification survives cleared cookies, whether results are verified on your server, whether native iOS and Android SDKs exist, and whether the pricing and policy are transparent. Fingerly is built around those four, and the demo shows exactly what it returns.

Device fingerprinting recognises a device; device intelligence goes further and describes whether it is automated, anonymised, emulated or tampered with. Fingerly does both, in one request.

No. Fingerly returns the visitor ID, the signals that fired and a suspect score, and never blocks a request by itself. Your application decides whether to allow, challenge, review or refuse.

Identify at the moment that matters, such as signup or login, and read the automation signals on your server. Fingerly reports driven browsers, declared scrapers, virtual machines and unusually busy devices, and you choose whether to challenge, slow or refuse.

Call identify and read the network signals. Fingerly classifies the connection as a commercial VPN, a datacenter or residential proxy, a Tor exit node or a hosting network, and flags a mismatch with the device’s own region, each with a confidence and a weight.

Store the visitor ID beside every new account and count accounts per visitor ID. Fingerly keeps the ID steady through cleared cookies and private windows, and device farm, emulator and anti-detect signals make a cluster more telling.

Identify at signup and again at redemption, store the visitor ID with each claim, and review devices that claim repeatedly. Hold the reward for a cluster instead of closing accounts, and keep a way for a genuine customer to be cleared.

Identify at signup, verify the result on your server, and combine automation, hosting network and repeat-device signals. Fingerly reports them without a captcha, and a gentle response such as email verification suits the uncertain cases.

Identify at login, recognise the devices an account normally uses, and step up verification only when a new device also carries automation, an anonymised network or tampering. Fingerly reports those signals, and the decision is yours.

Use the native SDKs. Fingerly’s Android SDK reports emulators and virtualised Android, and the iOS SDK reports the iOS Simulator, each as a signal with a weight you control. In browsers, virtual machines are reported instead.

Add the native SDK to your app. Fingerly’s Android SDK reports rooted devices and the iOS SDK reports jailbroken ones, along with instrumentation and interception, and the server decides, since an app can be patched to report anything.

Call identify and read visitor_is_new and the visitor ID. Fingerly recognises a returning device without storing anything in the browser, and visitor_confidence says how sure the match is.

Fingerly reports it from two halves: a native app can tell when its device looks provisioned for bulk use, and the server counts many near-identical devices behind one network. The cross-device half learns from your traffic for seven days before it adds to the score.

Look for emulators, provisioned devices and clusters of alike devices behind one network. Fingerly reports those as device farm, emulator and high activity signals, and you review the cluster rather than every user.

Yes. Tor exit nodes are reported at high confidence, and residential proxies as a signal with a confidence. Residential proxies are the hardest kind to tell from a real visitor, so use them beside device signals.

Not on its own. These have ordinary uses, so Fingerly ships them as context with small default weights, and they become meaningful alongside other signals such as automation or a farm.

Install the SDK for your platform, call identify at the moment that matters, send the request ID to your backend, read the stored result with a secret key and decide. The quick start walks through it, and development keys are free.

Add Fingerly’s native iOS SDK, call identify at signup, login or a reward claim, and verify the request ID on your server. In an app the device is a random install ID the SDK keeps, never the hardware.

Add Fingerly’s native Android SDK, call identify at the moments that matter and verify the request ID on your server. The SDK adds checks for emulators, root, cloned apps and instrumentation.

Yes. Fingerly’s React Native, Flutter and Lynx bridges sit over the native iOS and Android SDKs and send the same identify request as the web SDK, with the same response fields.

Yes. The JavaScript SDK has bindings for all six that identify after the page reaches the browser, so a server render shows the unidentified state and nothing needs guarding. They share one identification across a page.

Server SDKs exist for Node.js, Python, Go, Java, .NET, Ruby, Rust and PHP. Each reads an event with your secret key and verifies webhook signatures in one call.

Serve Fingerly from your own domain with a first-party proxy, either the Cloudflare Worker, the proxy inside each server SDK or a ready-made template. Every proxy gets its own random path on your site and nothing it sends back names Fingerly.

At the moments that matter: signup, login, checkout, a reward claim or a payout, not on every page render. Calling it where abuse is rewarded keeps both the cost and the friction low.

Yes. Development and staging keys are free and run the same detection as production, and the interactive demo identifies this browser only when you press its button. The pricing page has the rest.

Yes. The documentation provides an OpenAPI 3.1 document and a Postman collection, and the reference lists every endpoint, field, header and error.

Yes. Both the documentation and this site publish an llms.txt, and documentation pages have Markdown versions that are easy to paste into an assistant.

Run both side by side in monitoring mode, store the visitor ID next to your existing identifier, compare what each would have decided, and switch rules over one at a time. Nothing needs to be rebuilt at once.

It depends on where your visitors are and why you collect. Privacy laws such as the GDPR and the ePrivacy rules can treat device identifiers as personal data and may require a lawful basis, a notice and sometimes consent, so have your legal team review your use.

You decide the notice, the legal basis and any consent your visitors need. Fingerly’s SDKs collect and send nothing until you tell them consent is granted, which you can do when you load them or later from your consent banner.

Neither. The SDKs write no cookies and nothing to browser storage, and never show a permission prompt, picker or dialog on any platform.

Characteristics of the device and the browser or app, used to tell whether the device is being misrepresented and, in browsers, to recognise it. It does not read page content, form fields, keystrokes, mouse movement, the clipboard, contacts, photos or location services.

The servers and databases run in the European Union. Archived submissions, older analytics and encrypted backups are kept in object storage in the United States, and there is no residency setting to choose.

No. Visitor data is not sold, not shared between customers and not used for advertising. Identifiers are scoped to one customer, so the same device visiting two customers is two unrelated visitors.

Erase the visitor yourself from the console or through the management API, and their data is deleted. You can also write to support@fingerly.io and the team will do it for you.

Building gives you control but leaves you maintaining collection, recognition, detection and a network lookup as browsers and phones change. Buying means paying per identification, from $0.0025, and getting improvements without a release. The build versus buy guide compares them in detail.

No. Fingerly returns evidence and a score; your application decides. That is deliberate: the policy, the notice to your customers and the way to appeal a decision belong to you.

No privacy or security certification is claimed. Secrets are shown once and stored only as keyed hashes, public keys work only from the origins you list and secret keys are refused from browsers.