ODP is an OpenDocument deck, the native format of LibreOffice Impress. PDF is a frozen page layout with no heading structure a machine can rely on. LibreOffice sits between the two, and this page says exactly what happens to an ODP file on the way to becoming a PDF one.
What runs when an ODP file becomes PDF
LibreOffice 24.2, on a machine we rent and watch. Your ODP file is uploaded once, LibreOffice runs once, the PDF comes back, and neither file is kept. ODP to PDF is one of the 3649 pairs that engine was probed on with a real file, which is why it has a page here and why the pairs the probe could not prove do not.
What survives from the ODP into the PDF
The ODP page layout, exactly. LibreOffice renders your ODP file the way it would print it, so margins, columns, page breaks, headers and footers land in the PDF where the author put them.
Fonts, embedded in the PDF, so your ODP document reads the same on a machine that has never had those fonts installed.
ODP tables, drawn as they were drawn. Borders, merged cells and column widths survive into the PDF because they are painted rather than re-described.
One ODP slide per PDF page, with the deck order intact.
What ODP to PDF costs you
Editability. A PDF is the end of the line: nobody downstream can change a sentence without going back to your ODP file. Sometimes that is exactly the point, and sometimes it is exactly the problem.
Structure a machine can use. PDF has no heading hierarchy, no list semantics and no table model, so everything the ODP file knew about itself stops at the print stage. A program reading the PDF sees positioned glyphs and guesses the rest.
ODP speaker notes, animations and slide transitions. What lands in the PDF is the slide, not the performance. Measured on this pair: the notes are not in the file at all, which is the reassuring half of the story.
Where ODP and PDF files come from
ODP. LibreOffice Impress writes it natively, ISO/IEC 26300 again. A deck that arrives as ODP usually comes from someone who does not run Microsoft Office, and converting it is how you open it without installing anything.
If a model is going to read the PDF
Worth knowing before the PDF goes anywhere near an assistant: this is the wrong direction for that. A PDF is a set of positioned glyphs, and a model has to reconstruct the reading order before it can begin. If a machine rather than a person is going to read this ODP file, convert it to Markdown instead and skip the reconstruction entirely.
ODP to PDF, measured rather than promised
Running ODP to PDF against the real engine with a real file, LibreOffice wrote 20,929 bytes of PDF in 1.3 seconds, machine otherwise idle. That is one ODP file on one day and not an average, which is why the number is given together with the file that produced it.
The ODP to PDF verdict was reached by a format signature, meaning at least four bytes unique to the format were found at the right offset. Which check was used matters, because they do not all prove the same thing, and a status code of 200 proves nothing whatsoever about whether the PDF file has anything inside it.
The same ODP file, sent somewhere else
Other outputs the probe measured out of an ODP file, so the cost of choosing PDF can be read against something. Sizes do not compare across engines, because each family was probed with its own ODP witness file.
ODP to HTML: 12,295 bytes in 1.6 seconds, verified by reading the internal type and finding a witness word.
Other ways into PDF, and what they measured
Among the published routes into PDF, ODP is the number 13 largest output of the 26 measured. The witness files differ, so this ranks the probe run and not your document.
RTF to PDF: 11,917 bytes in 1.1 seconds.
CSV to PDF: 12,680 bytes in 1.0 seconds.
EPUB to PDF: 61,941 bytes in 1.9 seconds.
MOBI to PDF: 62,207 bytes in 1.9 seconds.
AZW3 to PDF: 62,065 bytes in 1.8 seconds.
What we will not pretend about ODP to PDF
An ODP file over 25 MB is refused before the upload finishes rather than after it, so you do not wait for a rejection.
An ODP to PDF run that passes 90 seconds is killed, and the LibreOffice process is killed with it. A run left behind would sit on one of the machine's two cores until somebody noticed.
LibreOffice is serialised on purpose, one document at a time per worker, because each soffice instance takes 150 to 300 MB on a machine with 3.8 GB. Measured ceiling: 23 ODP conversions in flight and roughly 0.9 a second sustained. Past that the queue answers 429 rather than falling over, which was tested at 32 at once.
One ODP file at a time, chosen in the browser. There is nothing else to set up and nothing else on offer.
ODP to PDF: what people ask
What actually converts my ODP file to PDF?
LibreOffice does it, 24.2, on a machine we rent and watch. Not a browser trick and not somebody else service: the ODP file is uploaded once, LibreOffice runs once, the PDF comes back, and neither file is kept afterwards.
How long does ODP to PDF take?
On the file the probe used, LibreOffice took 1.3 seconds and wrote 20,929 bytes of PDF. That is one real measurement on one real ODP file, not an average and not a promise about yours: a larger ODP takes longer, and past 90 seconds the run is stopped.
What do I lose going from ODP to PDF?
The one to know about first: Editability. A PDF is the end of the line: nobody downstream can change a sentence without going back to your ODP file. Sometimes that is exactly the point, and sometimes it is exactly the problem.
Is the PDF searchable afterwards?
Yes. The text in your ODP file is written into the PDF as text, not as a picture of text, so it can be searched and copied. What the PDF does not have is structure: no headings, no list model, no table model. It reads well to a person and parses badly to a program.
Is ODP to PDF free?
There is a free allowance every month, and one ODP to PDF conversion costs half a credit against it. When the allowance runs out the tool says so and stops, rather than quietly handing you a worse PDF.