You can try an Android app like ReadID to verify that the RFID chip is still functional:
https://play.google.com/store/apps/details?id=nl.innovalor.nfciddocshowcase
(not vouching for that app, but seems to have good reviews, could try running it in with mobile data disabled and uninstalling it before re-enabling mobile data)
Beyond that, make sure the ink of the machine-readable zone at the bottom of the biopage, and the other written information on is still clearly legible, and the photo has not been degraded, and the same for any visa stickers / foils / vignettes / stamps.
As long as the passport seems generally of the same condition, probably should not be a problem.
https://youtube.com/watch?v=lHZOVxYcobc
Make sure you place your phone close to the passport chip. If your passport's personal page is made from plastic then the chip is in this page.
I got this. Obviously, no one wants their passport to be damaged or wet, so I got this waterproof case made of hard plastic. Truth be told, it's rather clunky and unwieldy for everyday use, but when I'm not actively using my passport, that's where I store it. I am NOT gonna take any chances. I don't have to worry about my passport being squished inside my bag, nor do I have to worry about accidentally spilling coffee on it, or heaven forbid, my bag falling into a body of water.
It's pretty spacious. You can probably fit two standard-size passports, or one thiccboi. The link shows it in black, but I got the clear version.
> i want to make sure that my passport chip works fine
You can use the ReadID NFC app for Android or iPhone to test whether the RFID / NFC chip was affected:
https://play.google.com/store/apps/details?id=nl.innovalor.nfciddocshowcase
I tried checking all of my Amazon accounts but I couldn't find it. I think it's on my mom's Amazon account but I don't have the password to it and she's sleeping. I really think it's this one though.
It's very nice, and also has card slots on the inside (for passport card, global entry id, etc)
Here's an amazon link in case someone is wondering: https://www.amazon.com/Shvigel-Leather-Passport-Cover-Vintage/dp/B01AIKT8WW/