Merge PDF Files Online

Free Online PDF Merger

Free online PDF merger joins two or more PDFs into one document. Set the file order with the arrow buttons and download merged.pdf, with no sign-up and no watermark.

Document tooling from OnlinePCApps since 2013

Processed locally No sign-in No watermark No task cap
0
Bytes transferred
2+
Files per merge
∞
Merges per day
$0
Cost, permanently
Where a PDF merge is required

Online PDF Merger for Submissions, Scans and Case Files

Merge PDF files online when a form, a scan batch or a case file has to travel in one document. The online PDF merger treats all three like routine tasks rather than faults to repair.

Submission as a Single File

Applications, tenders, invoices and court filings frequently require one document. Separate PDFs for the form, the evidence and the legal annexes have to be merged into one PDF before submission.

Online PDF merger produces one file with the order set explicitly and the source pages unaltered.

Scans Produced in Batches

Sheet-fed scanners and mobile capture apps write one PDF per pass. A twelve-page contract scanned in three passes arrives as three documents.

Merge PDF files in sequence, with the file order set in the list before the merge runs.

Case Files Under Confidentiality

Contracts, medical records and financial statements cannot be sent to a third-party server for processing, whatever the retention policy states.

Processing runs on the device. No file is transmitted at any stage.
How it works

Merge PDF Files Online in Three Steps

instant PDF

Add Two or More PDFs

Drop PDF files onto the online PDF merger panel above, or click to browse. Every file up to 100 MB joins the list in the order added.

instant

Set the File Order

Move any file up or down with the arrow buttons, remove one with the cross or add more files. The list reads Ready to merge once two files are in.

instant

Merge and Download

Click Merge, then Download merged PDF. The PDF merger writes the output to merged.pdf and every source file stays untouched.

File order Arrow buttons, merged top to bottom
Add or remove Any file in the list, before the merge runs
Ready check Two files minimum, then Merge
Merge PDF Files No cost and no registration Desktop Edition For folder-level batches
The online app

Online PDF Merger on Any Operating System

The online PDF merger is a web page, so platform support follows browser support rather than an installer. Merge PDF files online on any of the four below.

On Mobile

Merge PDF files online from a phone browser. The 100 MB per-file limit applies there too.

On a Tablet

Tablet browsers on Android and iOS run the same online PDF merger. No application store step is involved.

On a Managed Device

Managed devices that prohibit installation still provide a browser, which is the only requirement.

On a Shared Machine

No installation occurs and merged.pdf lands in the browser download folder, nowhere else.

The OnlinePCApps online PDF merger is a free tool that combines two or more PDF documents into a single file. Files are added to a list, set in order with the arrow buttons and merged top to bottom into merged.pdf. Merge PDF files online whenever needed, with no count cap on the list. Folder-level batches and documents beyond available memory are handled by the desktop build.

Against the category

Online PDF Merger vs a Hosted Merger

Most free PDF mergers cap file size, cap tasks per day and hold the result behind a sign-in. The rows below set the online PDF merger here against that model.

This page This tool Runs in the browser A typical upload-based merger Transfers documents for processing
Where processing occurs On the device On the provider's servers
Free tier size ceiling 100 MB per file 10 MB to 15 MB per file
Free tier task cap None 2 to 3 tasks per day or hour
Watermark past the limit Never applied Applied by some providers
Point of failure None, work is local At download, once quota is spent
Retention after processing Nothing is held Deleted after one to two hours
Suitability for confidential files Unrestricted Constrained by policy
Speed by location Independent of distance Depends on distance to the servers

The right column describes the model hosted mergers share rather than any single named service. The left column is the online PDF merger above.

Merger data handling

PDF Merger Privacy and Data Handling

Retention policies are the standard reassurance in this category. A one-hour deletion window is typical, and it is only as strong as the operator behind it.

No retention policy applies here because no document is received. Nothing on this site accepts a file, and nothing runs on our side for this tool. The network panel in the browser developer tools records no transfer while a merge runs.

$ Network panel during a 12-document merge
→ external requests ....... 0
→ document upload ....... 0 requests
0
Bytes transferred
0
Accounts required
0
Documents stored
0
Trackers active
Merge behaviour

What the Online PDF Merger Does to Every Element

A PDF merge rewrites document structure while leaving page content untouched. The table sets out what is carried, remapped or lost. What a PDF keeps after an edit or redaction covers the rest.

ElementResultWhat happens
Page contentcarried unchangedContent streams, fonts and XObjects are copied byte for byte. No re-encoding occurs in the PDF merger, so nothing is degraded.
Page orderas arrangedFiles follow the sequence set with the arrow buttons in the online PDF merger. Pages inside every file keep their own order.
Page sizeretained per pageMixed A4 and Letter documents keep their original dimensions. Nothing is scaled to a common size.
Rotationretained per pageA page rotated in the source stays rotated in the output. Rotate pages first with the online PDF rotator when a scan came in sideways.
Bookmarksmerged and nestedEvery document's outline is preserved and placed under its own top-level entry in the combined file.
Internal linksremappedCross-references to pages inside the same document are rewritten to the new page numbers.
External linkscarried unchangedLink annotations pointing outside the document are copied as they were.
Form fieldscarried, names checkedAcroForm fields are preserved. Where two documents use the same field name, the second is renamed so values stay independent.
Digital signaturesinvalidatedA signature certifies one specific byte sequence. Merging produces a new document, so any existing signature no longer validates.
Tagged structurecarried where presentPDF/UA tagged structure is preserved when the source documents carry it. A merge cannot create tags that were never there.
Document metadataresetTitle, author and keywords are not inherited from any one source. The output from the PDF merger carries no metadata unless it is set afterwards.
AttachmentscarriedFiles embedded in a source document remain embedded in the output. PDF/A conformance is a property of every source and cannot be assumed to survive a mixed merge, which what PDF/A is and when it is needed explains.

Specifications this tool follows

PDF is an open standard maintained by ISO rather than a proprietary format, currently at PDF 2.0 with PDF 1.7 still the version most documents declare. The sources below cover the structures a PDF merge has to rebuild correctly: the page tree, the outline hierarchy and the interactive form dictionary.

ISO 32000-1 The PDF specification. Defines the document catalogue, the page tree and the cross-reference structures a merge has to rebuild for the combined file. PDF 1.7 reference The same specification, published by Adobe at no charge under arrangement with ISO. This is the copy most implementations are written against. PDF Association The industry body maintaining the standard. Publishes errata and the issue tracker implementations are expected to follow. Library of Congress The format description used for digital preservation, which sets out what a PDF has to retain to remain readable over time.

Signature behaviour is set out in the PDF specification, which is why a signature cannot survive a merge. What a signed PDF proves sets out what the signature covered in the first place.

Before merging

PDF Merger Notes Before Merging a Document

Four conditions block a PDF merge or alter the result. All four are stated with the reason and the order to follow before the PDF merger runs.

Encrypted Documents

A password-protected PDF cannot be read until the password is supplied.
Owner-restricted files may open but refuse extraction, which blocks the PDF merger.
Limit: Encrypted files are refused. Remove the restriction first with the online PDF unlocker. A merger that claimed to bypass encryption would be describing something other than a merge.

Signed Documents

A digital signature covers an exact byte sequence and cannot survive a merge.
The signature field is carried into the output but no longer validates.
Note: Run the PDF merger first and sign the combined document afterwards. Signing before merging wastes the signature.

Duplicate Form Fields

Two documents sharing a field name would otherwise share a value in the output.
The second occurrence is renamed so the fields stay independent.
Note: Renaming keeps data separate but alters the field name any downstream script expects.

Very Large Documents

Every file is checked against a 100 MB limit when it is added to the list.
File count is not capped, so a long list of small PDFs merges without trouble.
Limit: 100 MB per file. Shrink a heavier PDF first with the online PDF compressor, then add it to the list.

Check the List Before Merging

Read the numbered list from 1 downward, because that is the merge order. Move a file with the arrows until the sequence reads right, then click Merge in the PDF merger.

The list sets file order only. Page order inside a file is set with the online PDF organizer before merging.

Compress After, Not Before

Run the online PDF compressor against merged.pdf, which reduces size once, on the finished document. Compressing every source first re-encodes images twice.

Compression is lossy for images. Applying it twice degrades quality without a corresponding size gain.
Desktop edition

Desktop PDF Merger for Entire Folders

Two limits apply to the online PDF merger: 100 MB per file and one list of files per run. A folder of PDFs is a job for the desktop edition.

What the Desktop Build Covers

The online PDF merger takes one list of files per run and checks every file against a 100 MB cap, which covers most forms, scans and reports.

The desktop build streams from disk and writes incrementally, which removes the memory constraint entirely.

Online merger100 MB per file
Desktop toolconstrained by disk
Fully offline

No connection is opened after installation, which suits isolated networks and controlled environments.

No memory ceiling

Documents are streamed from disk rather than held in memory, so total size stops being a constraint.

Folder-level batches

Point it at a directory and merge every document in it under a naming rule.

Built for repeat work

Directories of documents processed under one rule, past the memory ceiling a browser applies.

Repeatable jobs

Save an order and a set of rules, then apply the same operation to a new set of files.

Runs disconnected

No connection is required after installation, which suits restricted networks.

Desktop Build Details Trial available · Windows 10 or later $39 one time · no renewal · 30-day refund period
Reference

Online PDF Merger Questions

The online PDF merger combines two or more PDF files into a single document. You add the files, set their order with the arrow buttons and click Merge. The result downloads under the name merged.pdf, with no account and no watermark.
No stage of the PDF merger depends on a quota. Hosted mergers commonly permit two to three tasks per day or hour on a free tier and enforce that limit at download, after the documents have been arranged. Here there is no point at which your completed job can be withheld.
No. Several providers stamp a watermark once a free allowance is exhausted rather than refusing the task outright. No allowance exists on the PDF merger here, so nothing is stamped on your output at any point.
No. Upload-based tools transfer documents to servers in a fixed region, so throughput depends on the distance to those servers. Processing on the device removes that variable, which is most noticeable for large documents outside Europe and North America.
No count limit is imposed by the online PDF merger, and no page limit either. Some providers cap a free merge at 100 or 200 pages. The one rule here is a minimum: you need at least two files in the list before the Merge button activates.
Yes. The online PDF merger checks every file against a 100 MB cap when you add it, and a heavier file is refused with a message. Shrink it first with the online PDF compressor, then add it to your list. Hosted free tiers commonly stop at 10 MB to 15 MB per file.
No. Processing runs in the browser on the machine holding the files. No endpoint exists that could receive them. This can be confirmed in the network panel of the browser developer tools while a merge runs.
Yes. Every file in your list has Move Up and Move Down arrows, and the online PDF merger joins the files top to bottom. Page order inside a file is not altered here. Set that first with the online PDF organizer, then merge.
Yes. The outline from every source document is retained and placed beneath its own top-level entry, so your combined file keeps a navigable structure rather than a flat page list.
AcroForm fields are carried into the output. Where two of your source documents use the same field name, the second occurrence is renamed so that entering a value in one does not populate the other.
No, and no PDF merger can preserve them. A digital signature certifies one exact byte sequence. Merging produces a different document, so the signature no longer validates. Sign your combined file after merging rather than before.
Not until the password is removed. An encrypted document cannot be read without it, and files carrying owner restrictions may open but refuse content extraction, which also blocks the merge. Unlock the file with the online PDF unlocker first, then add it to the PDF merger.
No. Page content is copied without re-encoding. Text stays as text, vector artwork stays vector and your images retain their original compression. A merge is not a conversion.
Title, author, subject and keyword fields are not inherited from any single source, because there is no correct choice among several. Your output carries no document metadata unless you set it afterwards with the online PDF metadata editor.
Yes. Every page retains its original dimensions, so a merged file may contain A4 and Letter pages together. Nothing is scaled or cropped to a common size.
Yes. The PDF merger runs in Chrome, Firefox, Safari and Edge, which covers Windows, macOS, Linux and ChromeOS. Nothing is installed on any of them.
Tagged structure is carried through where your source documents contain it. A merge cannot add tags to documents that were never tagged, so an untagged source produces an untagged section in the output.
Not directly. The online PDF merger takes PDF input only. Convert the pictures first with the online image to PDF converter, then add that PDF to your list like any other.
No. No watermark, no page limit and no trial period apply. Your output is the merged document and nothing else.
Serving a static page costs very little when the visitor's own device performs the work, and no document ever arrives here to be processed or stored. Revenue comes from the desktop edition, which covers folder-level and oversized jobs.
No. The PDF merger reads your source documents and leaves them exactly where they were. Discard merged.pdf and the originals are still in place.
More apps

More Tools to Work With PDF Files

All of them run online in the browser tab with nothing to install, alongside the online PDF merger. Split, compress, organize or lock the merged file in the same session.

Split PDF
Online PDF splitter to separate one document into several.
Compress PDF
Online PDF compressor to shrink the merged file.
Organize PDF
Online PDF organizer to reorder or remove pages first.
Add Page Numbers
Add page numbers online after the merge.
PDF Locker
Online PDF locker to password-protect merged.pdf.
OCR PDF
Online OCR to PDF to make scanned output searchable.
Image to PDF
Online image to PDF converter for images before merging.
All PDF Tools
All online PDF tools on the site in one list.
Authorship

Who Maintains This Online PDF Merger

OnlinePCApps Document Team

Document format engineering since 2013

Documented and reviewed by Last reviewed September 2026
13
Years in operation
110
Tools published
1
ISO standard applied
0
Documents retained

The company has published document and file format tooling since 2013, beginning with desktop software that parsed container formats directly rather than through an SDK. The online PDF merger applies the same approach: keep the controls to a file list and an order, merge PDF files top to bottom and write one conformant output file, merged.pdf.

Standards applied

ISO 32000 · PDF syntax Page tree · Object model AcroForm · Field dictionary FileReader API TextDecoder

Test coverage

Documents produced by Acrobat, Word, Excel, PowerPoint, InDesign, LaTeX and sheet-fed scanners Sources with conflicting AcroForm field names, to confirm values remain independent Outlines nested several levels deep, to confirm the combined bookmark tree Mixed page sizes and per-page rotation across the same merge Files with damaged cross-reference tables, to confirm a clear failure rather than silent corruption Output validated against a PDF conformance checker on every release
Team information Engineering notes Report a failing document
Found a PDF the online PDF merger merges incorrectly? Report it and it will be corrected.

Merge PDF Files Online Free

No installation, no registration and no watermark. Set the file order in the online PDF merger, click Merge and download merged.pdf.

Merge PDF Files Free, no account Desktop Edition For folders and archives
Merge PDF · Free