What can you change without setting up an app project?

Open a file or folder on macOS, Windows or Linux. Use it to edit a page or a configuration file. Running a complete web app can still require its own tools and setup.

What version are your changed lines compared with?

For an ordinary file outside Git, the built-in incremental diff compares your edits with the saved file on disk. In a Git project, the default Git target is the index, the staged snapshot prepared for your next commit. You can choose HEAD to compare with the current commit instead. Check the baseline before assuming a saved edit has been staged or committed.

When does the free evaluation turn into a purchase?

You can evaluate Sublime Text for free with no enforced time limit. The vendor requires a license for continued use. The personal license is a one-time $99 USD purchase and includes three years of updates. Business licenses are separate annual subscriptions. Sublime Merge is a separate Git client with an optional bundle.

What changes if you save the file before reviewing it?

On paper, draw a plain text file outside Git with one saved button label and a working copy with a new label. Then draw the same edit in a Git project. Keep the old label in the current commit and the new label in the staged snapshot and working copy.

Name each baseline
Use the saved file for the plain text comparison. In the Git sketch, the default staged snapshot matches the working copy. Choose the current commit instead and the label change becomes visible.
Try one local line if you want
Use a scratch text file you created. Edit a line and inspect the changed region before saving. No package or app process is needed.