YouTube URL algorithm?

Question

How would you go about generating the unique video URL\'s that YouTube uses?

Example:

• http://www.youtube.com/watch?v=CvUN8qg9lsk

Answer 1

You can use any library or some languages like python provides it in standard library.

Example:

import secrets


id_length = 12
random_video_id = secrets.token_urlsafe(id_length)

Answer 2

Your best bet is probably to simply generate random strings, and keep track (in a DB for example) of which strings you've already used so you don't duplicate. This is very easy to implement and it cannot fail if properly implemented (no duplicates, etc).

Answer 3

YouTube uses Base64 encoding to generate IDs for each video.Characters involved in generating Ids consists of

(A-Z) + (a-z) + (0-9) + (-) + (_). (64 Characters).

Using Base64 encoding and only up to 11 characters they can generate 73+ Quintilian unique IDs.How much large pool of ID is that?

Well, it's enough for everyone on earth to produce video every single minute for 18000 years.

And they have achieved such huge number by only using 11 characters (64*64*64*64*64*64*64*64*64*64*64) if they need more IDs they will just have to add 1 more character to their IDs.

So when video is uploaded on YouTube they basically randomly select from 73+ Quintilian possibility and see if its already taken or not.if not use it otherwise look for another one.

Refer to this video for detailed explanation.

Answer 4

Typically you're hiding a numeric identifier in the form of something that doesn't look numeric. One simple method is something like base-36 encoding the number. You should be able to pull that off with one or another variant of itoa() in the language of your choice.

Answer 5

I suggest using a perfect hash function:

Perfect Hash Function for Human Readable Order Codes

As the accepted answer indicates, take a number, then apply a sequence of "bijective" (or reversible) operations on the number to get a hashed number.

The input numbers should be in sequence: 0, 1, 2, 3, and so on.