About batch compress PDF
Compressing files one at a time is the kind of work that should not exist, and batching it removes the tedium without changing what happens to each file. Every PDF is opened, processed and closed in turn — sequentially and independently — and the results are collected into a single ZIP. Sequential processing is a deliberate choice rather than a limitation: it keeps peak memory to roughly one document at a time, which is what makes a large batch feasible in a browser tab at all. Independence is what makes the batch dependable. If the eleventh file is corrupt or password-protected, it is marked failed with the reason, and files twelve through forty still process and still appear in your download. You never lose a completed batch to one bad input. And because nothing is uploaded, nothing waits behind anyone else’s job: the only thing between you and the ZIP is your own processor.
How to batch compress PDF
- 01
Add your PDFs
Drop in two or more files, or a whole folder’s worth at once.
- 02
Choose a level
Balanced suits most documents. Use high quality for anything with photographs you care about.
- 03
Run the batch
Files are processed one after another with a live progress list showing each result.
- 04
Download the ZIP
Every successful file is included, with per-file size savings reported.
What this tool does
- One operation across an unlimited number of files — no artificial cap
- Per-file results with before and after sizes, so you can see what each one saved
- A failed file is reported with its reason and never blocks the rest of the batch
- Sequential processing keeps peak memory to about one document at a time
- Nothing uploaded, so no queue, no rate limit and no size ceiling imposed by a server
Limitations worth knowing
Every PDF tool has constraints. Stating them plainly is more useful than discovering them halfway through your work.
- The real constraint is device memory. Many small files are unproblematic; a handful of very large scanned documents is the harder case.
- One compression level applies to the whole batch — per-file tuning needs the single-file Compress PDF tool.
- Password-protected files cannot be processed in a batch, since each would need its own password prompt.
- A PDF that is already efficiently compressed may shrink very little, and reprocessing images can occasionally add a few bytes.
How your file is handled
This tool runs entirely inside this browser tab. When you choose a file, your browser reads it from your own disk and hands the bytes to JavaScript running on this page — no network request carries your document anywhere. You can confirm that yourself: open your browser’s developer tools, switch to the Network panel, and run the tool. You will see no upload.
Nothing is stored after the fact. Closing or reloading this tab discards the file, the result and everything derived from them, because none of it ever left your machine. Read how local processing works.
Questions about batch compress PDF
How many files can I compress at once?
There is no imposed limit. Because processing happens on your device, the constraint is memory rather than a policy — dozens of ordinary documents are fine, while a few hundred-megabyte scans are what actually strains a tab.
What happens if one file in my batch is broken?
It is marked failed with the reason, and every other file still completes and is included in the ZIP. A single bad input never costs you the batch.
Is a batch slower because other people are using the site?
No. Nothing is uploaded and there is no server queue, so no other user’s work affects yours. Speed depends only on your own processor and the files themselves.
Can I use different settings for different files?
Not within one batch — a single level applies throughout. Split the files into groups and run a batch per group, or use the single-file Compress PDF tool where individual tuning matters.
Tools that pair with this one
- Compress PDFMake a PDF smaller by re-encoding its images and cleaning up its internals.
- Batch Rotate PDFStraighten sideways pages across a whole set of scanned files.
- Batch Watermark PDFStamp the same mark across every page of every file in one pass.
- Batch PDF to ImagesRender every page of every file to an image, organised per document.
- Batch Merge PDF FilesCombine a large set of files into one document, ordered automatically.
- Batch Images to PDFTurn each image into its own PDF, sized how you choose.