What this can't fix (and why)

This tool works on the vast majority of web pages, but a few things are out of its reach:

• With the userscript, ads, embedded videos, and some comment sections might not resize. These are often a small "page within the page," loaded from a different website, and browsers don't let a userscript reach inside that, for safety reasons. The Firefox add-on can: it resizes most of them along with the rest of the page.
• A few sites hide extra content inside sealed, locked-down components nothing outside can touch. This is rare in practice.
• Text inside a small, fixed-size box — like a single-line title — might get cut off if you make it a lot bigger. This can happen with your phone's own zoom too; it's a limitation of the page's own design, not something specific to this tool.
• Occasionally, one specific piece of text on a page may resist resizing. Some sites keep re-applying their own text size while you use the page, and some parts of a page that load late may stay at their normal size. This is uncommon.
• If the site changes its own text size while you read — with its own text-size or reading-mode button, or when you open a menu — that text may keep the size it had before. Reloading the page fixes it. (Turning your phone or resizing the window is fine: the page adjusts.)
• Boxes sized to fit their text can grow with it. On a few pages, a very large size can make such a box wider than the screen.
• The Firefox add-on can't work on Firefox's own pages (settings, the add-ons page, the PDF viewer), on Mozilla's add-on site, or on sites where you've turned off its permission to access the site.

None of these affect the rest of the page — everything else still resizes normally.