LibreOffice or Microsoft Office compared

On a migration I did for a three-person office, the entire project went smoothly except for one spreadsheet. It had a macro somebody had written years earlier, it rendered differently in LibreOffice, and fixing it took an hour. That hour was the single real cost of the whole changeover, and I lead with it because every honest comparison of these two products comes down to where your version of that spreadsheet is.

Where they are genuinely equivalent

For writing documents, building ordinary spreadsheets and making presentations, the two are close enough that arguing about it is a waste of an afternoon. Both have the formatting, the styles, the formulas, the charts. Both open and save the other's formats. The interface differs, and for someone who has used one for fifteen years that difference is annoying for a week and then is not.

I say this as somebody who genuinely uses both, because clients send me files and I am not going to pretend one of them does not exist. For the work most people do in an office suite, the choice is not a technical question.

Where the differences are real

Three places, and they are worth knowing precisely rather than vaguely.

Complex documents that travel. A plain document moves between the two perfectly. A document with elaborate formatting, precise layout, embedded objects or tracked changes moves imperfectly, and the imperfection shows up as a shifted image or a page break in the wrong place. If your work involves sending highly formatted documents to somebody who will open them in the other product and judge you on the result, this is a real problem and not one to wave away.

Macros. These do not transfer. The languages are different and anything beyond trivial has to be rewritten. For a company with a decade of accumulated automation in spreadsheets, this is the whole decision and everything else is noise. My three-person office had one macro and an hour of work. An accounting firm with forty of them has a project, and I would tell them so rather than start it.

Real-time collaborative editing. Several people typing into the same document simultaneously, in a browser, is the thing the commercial suite has spent a decade perfecting and it shows. The open alternatives have it and it works, but if this is how your organisation genuinely operates, be honest about which tool is better at it.

The part that is not about features

Underneath the comparison sits a difference that outlasts any feature list: the file format.

The open suite's native format is an open standard — a documented specification that anybody may implement. That is not an abstract virtue. It means a document written today can be opened in thirty years by software that does not exist yet, because the specification describing it is public and permanent. Nobody has to still be selling a product for your archive to remain readable.

One honest qualification, because the simple version of this argument is unfair: the commercial suite's format is also a published standard. The difference is practical rather than formal — the open one is small enough that several independent programs implement it completely, and the other is large enough that in practice only its author does.

I care about this professionally, because I deal with people who need to keep documents for a decade or longer by law. Format lock-in is the quietest and most expensive kind of dependency: it costs nothing until the day you want to leave, and then it costs everything at once.

The second structural difference is what happens to a document you never open. An offline suite is installed on your machine and keeps working — no account, no subscription check, no connection. A document written in it is yours in the simple, physical sense. Whether that matters to you is a genuine question with a legitimate "no" available.

How I actually decide with a client

One question, asked before anything else: show me the most complicated file you work with regularly.

Then we open it in the open suite, together, and look. That takes ten minutes and it produces a better answer than any amount of feature comparison, because it tests the actual work rather than the general case. Most of the time it opens correctly and the conversation is over. Sometimes it does not, and then the honest recommendation is to keep what they have, possibly on one machine while everything else moves.

Mixed environments work fine, incidentally, and the purist position that everything must move is the fastest way to make a migration fail. One machine keeping the commercial suite for the two documents that need it, while the other six run the open one, is not a defeat. It is the correct answer to a specific situation, and pretending otherwise would be exactly the kind of ideology-over-evidence thinking I object to in the other direction.