Guide

How to upgrade ASP.NET Zero without losing customizations

Quick answer. Treat the upgrade as a three-way merge between the old template, the new template and your code. Apply template changes only where you never edited, review every overlap by hand, validate with a real build and tests, and keep a rollback plan.

Why ASP.NET Zero upgrades are hard

You start from a generated template and then customize it, so your code and the vendor’s template diverge.
Each new template version changes the same files you edited, so plain text diffs bury meaningful conflicts in noise.
The longer you wait, the more versions pile up and the larger the single jump becomes.

The three-way merge model

Base: the template version you started from. Theirs: the target template. Yours: your current code.
A change that exists only in Theirs can be applied safely. A change that exists in both is a conflict.
Comparing C# syntax trees rather than lines lets the merge reason about members, not whitespace.

A safe process

Create a branch from a green baseline and tag it.
Update packages and verify with a real restore and build.
Merge template changes; resolve each conflict deliberately and write down why.
Review EF Core migrations before they touch any database.
Run the full test suite and a vulnerability scan, then open a pull request.

Where UpgradePilot fits

UpgradePilot automates the steps above — template download, AST comparison, semantic merge, package upgrades, migration checks, validation and the pull request.
It leaves the judgment calls to you: every conflict is flagged rather than silently resolved.
See the ASP.NET Zero guide for what runs and what you still review.

Next steps

See the technology guides, the documentation hub, or request a free upgrade assessment.