I am trying to understand crc32 to generate the unique url for web page.
If we use the crc32, what is the maximum number of urls can be used so that we can avoid duplicates?
What could be the approximative string length to keep the checksum to be 2^32?
When I tried UUID for an url and convert the uuid bytes to base 64, I could reduce to 22 chars long. I wonder I can reduce still further.
Mostly I want to convert the url (maximum 1024 chars) to shorted id.
The right way to make a short URL is to store the full one in the database and publish something that maps to the row index.  A compact way is to use the Base64 of the row ID, for example.  Or you could use a UID for the primary key and show that.
Do not use a checksum, because it's too small and very likely to conflict.  A cryptographic hash is larger and less likely, but it's still not the right way to go.
CRC32 to make short URL for web