Organise PDF
Merge PDFs
Combine 2 to 20 PDFs in order while carrying over supported structure.
Choose files
Choose between 2 and 20 PDF files, up to 120 MB in total.
Merge PDF files
Combine PDFs in a selected order while retaining supported navigation, forms, attachments and document settings in the assembled copy.
Use the first PDF as the base document
The merge starts with the first selected PDF and adds the remaining files to it. The first file supplies the base bookmarks, fillable forms, attachments, language settings and viewer preferences.
Place the document with the required base structure first, then arrange the other PDFs in the order their pages should appear. The source files remain separate and unchanged.
Carry supported structures into the merged file
Bookmark trees from later files are merged and their targets are updated to the new page positions. Supported form fields retain their values, and embedded file attachments remain associated with their source documents.
Page-label sequences are preserved for each source, including roman-numeral front matter and numbered bodies. Named destinations are retained and deduplicated when two files use the same name, with a warning in the result.
Internal navigation that points to retained source pages is updated for the new page positions. Review links that use named destinations when the result reports a duplicate destination name.
Review merge warnings
Merging changes the document bytes and invalidates digital signatures in the source files. The result reports any signed input and any damaged file that required repair before its pages could be combined.
When accessibility tagging cannot be combined into one supported structure, it is removed and reported instead of leaving incomplete tags in the merged PDF. Review every warning before using the result.
Check the assembled PDF
Before download, the assembled file is reopened and checked for the expected page count from each source, bookmark counts and targets, supported form fields and embedded attachments.
A failed check ends with an error instead of a download. Open the saved copy in another PDF reader and confirm file order, page order, navigation, form values and required attachments.
The merge runs in this browser, and the selected PDFs are not sent to a document-processing server. The output is a separate file, so keep the sources until the assembled copy has passed review.
Questions
How are multiple PDFs combined?
Choose the files, set their order and merge them. The first PDF supplies the base structure, and the source files remain unchanged.
Are pages converted to images?
No. Pages remain PDF pages, while supported bookmarks, forms, attachments, labels and destinations are carried into the merged copy.
How is the file order changed?
Move each file up or down before starting the merge.
Which PDFs must be prepared before merging?
Password-protected PDFs must be unlocked first. Very large files may also exceed the memory available on your device.