Merge PDF
Combine PDFs into one file, in the order you choose. Your PDFs are processed in this browser tab and never uploaded.
- No file upload
- No sign-up
- No daily limit
This early version works with a limited set of PDFs up to 32 MB (25 MB on iPhone and iPad), including PDFs with an AES-128 password. Forms, comments, layers, attachments, newer compression and AES-256 aren't supported yet. Your original is never changed.
What's supported?
This version accepts PDF 1.x with complete classic cross-references, and stream lengths stored directly or, in unencrypted files, in a separate object. Files with later edits saved on top are accepted when they are unencrypted and every edit uses that classic form in a way this version has qualified; only their latest version is used, and earlier versions are checked but never copied. Object streams, cross-reference streams, hybrid files, other forms of later edits and PDF 2.0 are refused. Files with forms, layers, attachments or annotations other than links are refused until preservation is qualified, and so are bookmarks, links, tags and metadata streams in forms this version has not qualified. Inline images in forms this version has not qualified, pages that set default colour spaces, unsupported content encodings and incomplete inspection also cause a refusal. Encrypted input is limited to Standard R4 AES-128 with matching string and stream filters; AES-256 and other unqualified routing are refused. Passwords in this compatibility profile use single-byte characters and the first 32 bytes. Full rewrites create a new file identity. Unsupported inputs are not converted. This operation writes new document information; source titles, authors and dates are not retained. It does not keep bookmarks, tags or document metadata either, and it removes links to pages that are not in the new file.
Files containing any of these are refused:
- digital signatures or signature fields
- XFA forms
- interactive form fields
- tags or marked content, in forms this version has not qualified
- document or object metadata streams, in forms this version has not qualified
- output intents (the colour profiles that PDF/A archival and PDF/X print files often carry)
- embedded files or file attachments
- associated-file relationships
- optional content layers
- page annotations, in forms this version has not qualified
- bookmarks, destinations or document navigation, in forms this version has not qualified
- custom page labels, in forms this version has not qualified
- document actions or multimedia, in forms this version has not qualified
- externally stored stream data
- document features outside the current supported profile
Drop PDFs here
or choose them from your device
Checking this device's limit…
Request-body observations · Observation unavailable
Request-body observation scope
Observed window APIs: none. Calls are counted since observation started. Measured sizes describe supported supplied bodies at the API call, before native conversion, including failed attempts; delivery is not measured. Multipart values are a lower bound, and streams or unmeasurable bodies have unknown sizes. Other APIs, workers, service workers, headers and earlier traffic are outside this counter. This is not a total network-byte count.
How to merge PDF files
- Drop your PDFs onto the box above, or press Select PDF files.
- Use the up and down buttons to set the order.
- Press Merge. Your browser does the work, and the progress bar is real.
- Download the result. It is already in memory, so there is no wait.
Password-protected files within the supported document profile can be opened with the password. You will be asked for it, and it never leaves your device either. The merged file is not password-protected; use Protect PDF afterwards if you need one.
What merging actually does to your file
Merging copies each source document's page objects, fonts and embedded images into a single new PDF, then rebuilds the cross-reference table. Because nothing is re-encoded, text stays selectable, vector graphics stay sharp. The final size depends on the objects each document contains and how they are rewritten.
Existing bookmarks and links are outside the current supported profile. Their targets can depend on document-level references that change when pages are copied. Files containing navigation or page annotations are refused before merging until their preservation is qualified.
Forms and other complex features are refused. This version accepts a restricted page-content profile. It does not convert files with form fields, tags, layers, attachments or metadata/profile streams. A refusal explains the limitation and leaves your original available. The page on why a PDF is refused covers each reason.
Common questions
Are my files uploaded anywhere?
No. The merge runs in a Web Worker inside this browser tab. The request-body observer in the file selector reports attempted calls to selected page APIs after observation starts. It distinguishes measured payloads, multipart lower bounds and unknown sizes. Site and asset requests can still appear in your network tab; this observer does not establish successful delivery, total network bytes or complete privacy coverage.
Is there a size or daily limit?
No daily limit and no account. The size limit is 32 MB per PDF (25 MB on iPhone and iPad), and Merge combines up to 32 MB in total, because the merged file has the same 32 MB limit. The figure for your device is shown in the file selector once the page has loaded. Some complex PDFs may still exceed your browser's available memory.