# News: An example code for converting URL generated by "Concatenate" to the "Replace (Backward compatibility mode)" specification has been published in LIFF

An example code for converting URL generated by "Concatenate" to the "Replace (Backward compatibility mode)" specification has been published in LIFF

As announced on November 20, 2020, on March 1, 2021, Replace (Backward compatibility mode) in Method for converting additional information in the LIFF URL on the LINE Developers Console will no longer be available. After this change, all LIFF and LINE MINI App URLs will be opened with Concatenate.

Accordingly, we published a document introducing how to address cases in which the Replace (Backward compatibility mode) specification still requires a transition to a secondary redirect URL, even after you migrate your LIFF app or LINE MINI App to Concatenate.

This document introduces the function and logic that redirects users to a URL based on the Replace (Backward compatibility mode) specification when they click on a secondary redirect URL generated by Concatenate.

When you use the conversion code

We will provide this document for a limited time only.

Example code for converting URL generated by "Concatenate" to URL of "Replace (Backward compatibility mode)" specification in the LIFF documentation is intended to support the migration to Concatenate, due to the discontinuation of Replace (Backward compatibility mode). Some time after the discontinuation of Replace (Backward compatibility mode), we may delete the page. If you wish to check the conversion method even after the page is deleted, download the function that converts secondary redirect URL generated by "Concatenate", and refer to the code as necessary.