Desktop Publishing Pro
Desktop Publishing opens .pub files made in Microsoft Publisher - from Publisher 98 to Publisher 2019 and Microsoft 365 - on your own PC. Nothing is uploaded, and your .pub file isn't changed. A short report says exactly what came across and what didn't.

Use File > Open, drop the .pub file onto the page, or right-click it in File Explorer and choose Open with > Desktop Publishing.
It lists the pages, text boxes, pictures, shapes and tables that came across, and anything that didn't - WordArt becomes styled text, for example, and text wrap around pictures isn't converted.
Free: look through every page as a preview. To edit it, start the 7-day free trial of Desktop Publishing Pro - the file unlocks where it is.
Save it as a Desktop Publishing file (.m2dp). From then on it's an ordinary publication: linked text, pictures, master page and all.

Help: Open a Publisher (.pub) file has every option in detail.
Part of Desktop Publishing Pro. Desktop Publishing is free. Desktop Publishing Pro is a one-off £9.99 upgrade inside the Windows app, bought through the Microsoft Store - no subscription, no account. Try it free for 7 days.
Files from Publisher 98, Publisher 2000 and Publisher 2002 to 2019 and Microsoft 365. Password-protected files can't be opened.
Very close, but not always exactly. Pages, text and its formatting, pictures, shapes, lines, tables, groups and linked text boxes come across. The report lists what doesn't: WordArt (shown as styled text), gradient fills (shown as a solid colour), border art (a plain border) and text wrapping round pictures. Fonts that aren't on your PC are shown with a similar font.
No. The file is read and converted on your PC, by the app. It works offline.
Looking at them is free: every page, as a preview. Editing and saving them is part of Desktop Publishing Pro - try it free for 7 days.
No. It's only read. You save your edited copy as a .m2dp file.

Flyers, newsletters, posters, cards, certificates, timetables and more - every part editable.

Link text boxes and a story carries on from column to column and page to page.

Tables for timetables and price lists, 21 shapes, and text effects for headlines.

Certificates, name badges, place cards and labels from a CSV or Excel list.

Month and year calendars with UK bank holidays, and folded booklets in page order.

Save PDFs at the exact page size with real text; Pro adds bleed and crop marks.
Desktop Publishing is free, in your browser and on Windows. Desktop Publishing Pro is a one-off £9.99 in the Windows app, with a free 7-day trial.