Converting
How to Batch Process PDF Files
Convert, compress or split many PDFs at once without repeating yourself — how to structure the work and where batching stops being sensible.
Doing one PDF is a task. Doing sixty is a project, and the way you organise it determines whether it takes ten minutes or an afternoon.
Which operations batch well
| Operation | Batches well? | Why |
|---|---|---|
| Compress | Yes | Same settings apply sensibly to every file |
| Convert images to PDF | Yes | Uniform treatment is usually correct |
| Convert PDF to images | Yes | One resolution for the whole set |
| OCR | Yes | Same language and settings throughout |
| Merge | Partly | Order matters, so the sequence needs deciding first |
| Split by ranges | No | The right split points differ per document |
| Redact | No | Every document has to be read and judged individually |
Prepare before you start
- 1Put every file in one folder and nothing else in it.
- 2Rename them with a numeric prefix if order will matter later.
- 3Run one file through first and check the result before committing the rest.
- 4Work in batches of ten or twenty rather than all at once, so a failure costs you one batch.
- 5Keep the originals until you have verified the outputs.
Memory limits in the browser
Browser-based tools do the work on your own machine, so a batch of large scans can exhaust the tab's memory — Chrome will reload rather than warn. Smaller batches are not a workaround so much as the right way to do it: they finish faster in practice and a failure costs you less.
When to script it instead
If this is a recurring job — every invoice each month, every scan into an archive — write it as a script with a command-line tool and run it unattended. Browser tools are excellent for the work in front of you and the wrong shape for a scheduled pipeline.
The dividing line is roughly whether you will do it again. Once: batch it by hand. Every week: automate it.
Do it now
Compress PDF
Reduce file size while maintaining quality. It runs in this browser tab — your file is not uploaded anywhere.
Open Compress PDFFrequently asked questions
How many files can I process at once?+
It depends on their size and your device. Ten to twenty ordinary documents is comfortable; large scans should be done in smaller groups.
Can I apply different settings per file?+
Not within one batch. Group the files by the settings they need and run a batch per group.
Do I get one download or many?+
Multiple outputs are normally delivered as a single ZIP, which is also the easiest thing to unpack in order.
Should I batch redaction?+
No. Redaction requires judgement about each document. Batching it is how sensitive information gets missed.