Convert Salesforce Ids from 15 to 18 characters

This page is a system converting many Salesforce IDs (vertical list) from 15 characters into their 18 characters version.

Paste your list of Ids into the first text area
It is safe, no data will be transmitted over the network (local processing).
You can paste thousands of lines, it will create a list of the same Ids converted to 18 Characters.
There is no difference with the API or within a SOQL query to use either an Id15 or an Id18.