I am using fingerprintjs reference: /

It works fine and generate same code every time i use a particular page. But when the same code and page is executed on private mode of the same browser it generates different code.

var fingerprint = new Fingerprint({
                       ie_activex: true,
                       screen_resolution: true,
                       canvas: true}).get();
console.log(fingerprint);

What should i do to make it same on private mode.

I am using fingerprintjs reference: http://valve.github.io/fingerprintjs/

It works fine and generate same code every time i use a particular page. But when the same code and page is executed on private mode of the same browser it generates different code.

var fingerprint = new Fingerprint({
                       ie_activex: true,
                       screen_resolution: true,
                       canvas: true}).get();
console.log(fingerprint);

What should i do to make it same on private mode.

• javascript
• cross-browser
• fingerprinting
• fingerprintjs

• Is there a reason why this matters? The accuracy isn't 100% anyway. – t.niese Commented Jun 16, 2014 at 8:16
• Yes, because of the private browser this matters! Now, I have to recognize the user machine or just browser (both default and private). How would i do. I am using fingerprintingjs – Sheraz Ali Commented Jun 16, 2014 at 9:58
• Private and default browsing will/may have different behaviors (e.g. different loaded plugins) so it is likely that they may have different finger prints. So if you would explain why you need this then it would probably be possible to give a solution. – t.niese Commented Jun 16, 2014 at 10:10
• We have a website and we are paying $10.00 for each signup of user to i2c. Now, It usually happens we got 100-150 signups with same name almost same emails with difference of very short time period. Now We want to block that user for certain time. – Sheraz Ali Commented Jun 16, 2014 at 10:16
• @t.niese the problem isn't that the fingerprints are different it's that they are totally different, basic hash algorithms are inappropriate as they exhibit the "avalanche effect", while the appropriate behavior is that similar devices should have similar hashes. Ideally the similarity of the hashes should enable us to determine a probability that the two hashes belong to the same device/user. – user3338098 Commented Mar 17, 2017 at 18:50

2 Answers 2

Fingerprintjs first builds a big string with browser info and then hashes this string. You can pare this string in both regular and private mode and see what's different, ie. what information browser stops returning when in private mode. Having this information you'll be able to decide on future steps. For example customise the library to suit your particular needs.

Fingerprint JS is now providing the same id across normal sessions and incognito sessions,

Give it a try on https://fingerprintjs./

and try opening it in Incognito.

It still does not support cross-browser cases.