Merge PDF Files — Free & Private
Combine multiple PDF files into a single document in seconds. Drag to reorder, add as many PDFs as you need — runs entirely in your browser, nothing is uploaded.
In short: add your PDFs, put the files in order, optionally take only some pages from each, and press Merge. Links, form fields and a bookmark per file come through, and everything happens on your device.
- Is it free, and is there a limit?
- Yes, free, with no file count, page or hourly limit. Nothing is sent to a server, so there is nothing to meter.
- Can I take only some pages from a file?
- Yes. Each file has a Pages box: blank for all of it, or a range such as 1-3, 7.
- Can I merge a password-protected PDF?
- Yes. Restricted files open automatically; a file with an open password asks for it, and the password stays on your device.
- Can I merge two scans of the same pages?
- Yes. Interleave takes the fronts and the backs and puts them in reading order, even when the backs were scanned backwards.
- Do links and form fields still work?
- Yes. Internal links are re-pointed and form fields stay fillable; the source files’ own bookmarks do not survive, so one bookmark per file is built instead.
- Does merging change the quality?
- No. Pages are copied as they are; nothing is re-rendered or re-compressed.
How to Merge PDF Files
Drop 2 or more PDF files onto the tool, or click to browse and select them.
Drag the files up or down to set the exact order they'll appear in the merged PDF.
Hit "Merge PDFs" — combining runs instantly in your browser using PDF-lib.
One click downloads your merged PDF — all pages, original quality, ready to share.
Why Use Convertlo to Merge PDFs?
- 🔒 100% Private — files never leave your browser, zero server uploads
- 🆓 Free forever — no account, no watermark, no file size cap per session
- ↕️ Drag to reorder — set any page order before merging
- 📄 Original quality preserved — pages copied directly, no re-encoding
- ♾️ No page limit — merge PDFs with hundreds of pages
- 📱 Works on mobile — works on any device with a modern browser
Features
100% Private
No server. No upload. Your PDFs stay on your device the whole time.
Drag to Reorder
Drag any file up or down in the list to control page order.
Instant
Merging completes in seconds for typical documents.
No Quality Loss
PDF-lib copies pages without re-encoding — full original quality.
No Limit
Add as many PDFs as you need. No file count cap.
Mobile-Ready
Works on iPhone, Android, tablet, and desktop.
Interleave, blank pages, file names and a contents page
Under More options are four things Sejda and iLovePDF keep in their “more options” panels, all free here. The button’s label lists whichever are switched on.
- Interleave two scans. A scanner without duplex gives you the fronts, then the backs — usually backwards, because you flipped the stack. Add the fronts file first and the backs second, tick Interleave, and the pages come out 1, 2, 3, 4… If the backs were scanned in order, untick “runs backwards”.
- Blank pages for double-sided printing. A 3-page file followed by another would put the second file’s first page on the back of the first file’s last sheet. A blank page after each odd-length file keeps every file starting on a front.
- File names in the footer. Each page gets its source file’s name in small grey text at the bottom left, so a printed bundle can be taken apart again.
- A contents page. One line per file with the page it starts on, each line a link to that page. Page numbers count the contents page itself.
Interleaving re-orders pages, so link repair and per-file bookmarks are switched off for that merge; scans rarely carry either.
Capabilities at a glance
What this tool does and does not do, stated plainly. The “No” rows are the point, not an omission.
| Capability | Supported | Detail |
|---|---|---|
| What it does | ||
| Merge any number of PDFs | Yes | No file count cap. |
| Take only some pages from each file | Yes | A Pages box per file, such as 1-3, 7. |
| Rotate a file while merging | Yes | Per file: 90°, 180° or 270°. |
| Reorder on a phone | Yes | ▲▼ buttons as well as drag; drag alone never fires on touch. |
| Sort by name or size | Yes | Name sort is numeric, so scan-2 comes before scan-10. |
| Interleave two scans (fronts + backs) | Yes | With the backs reversed or in order. |
| Blank page for double-sided printing | Yes | After any file with an odd page count, so each file starts on a front. |
| File name in each page’s footer | Yes | Small grey text, in any language the fonts cover. |
| Contents page with links | Yes | At the front, one line per file with its page number. |
| Keep each file’s own bookmarks | No | They do not survive a page copy; one new bookmark per file is built instead. |
| Make all pages the same size | No | Pages keep their own sizes. |
| Input | ||
| A PDF with a permissions password | Yes | Opened automatically. |
| A PDF with an open password | Yes | The page asks for it; it never leaves your device. |
| File count, page or task limit | No | Sejda’s free tier allows 2 tasks an hour, 200 pages and 50 MB. |
| Output | ||
| Internal links still work | Yes | Re-pointed at the merged pages; links to pages you left out are removed. |
| Form fields still fillable | Yes | A clash of field names is resolved by renaming after the file. |
| Pages re-rendered | No | Copied as they are, at full quality. |
| Digital signatures stay valid | No | A signature covers one document; a merged file is a different one. |
| How it runs | ||
| Nothing is uploaded | Yes | The files never leave your device. |
| Signup | No | There is no account. |
| Offline use | No | The page and its PDF library load from the network first. |
What free PDF mergers hold back
Merging whole documents is the easy half. The part people actually need — taking pages 2 to 5 of one file and only the signature page of another — is where the free tiers stop. Checked on 9 September 2026:
| Tool | Free-tier ceiling | Pick pages per file? | Files uploaded? |
|---|---|---|---|
| Convertlo | No limit — no file count, page count or hourly quota | Yes, free | No — merged on your device |
| Smallpdf | 2 operations per hour | Paid | Yes |
| Sejda | 2 tasks per hour · 200 pages · 50 MB | Paid | Yes |
| iLovePDF | More generous, still capped without an account | Paid | Yes |
The reason we can be uncapped is the same reason we cannot offer a few things they do: there is no server. Your PDFs are read by JavaScript in the page you are looking at, combined there, and handed back as a download. No queue to ration, no storage to pay for, and nothing to leak — which matters if the thing you are merging is a contract, a payslip or a medical letter.
What merging cannot preserve, and why
A merge copies pages. It does not copy the structures that point at pages, and the most visible of those is the bookmark tree — the clickable table of contents down the side of a PDF reader. We tested this rather than assuming it: build a PDF with a real outline, merge it, read the result back, and the outline is gone. That is true of every browser-based merger using this approach, ours included, and we would rather say so than let you find out after a 200-page merge.
What does survive: the page content itself at full quality (nothing is re-encoded or re-compressed), links inside the page text, embedded fonts, and form fields as drawn. What does not: bookmarks, the document outline, and attachments held at the file level rather than on a page.
If bookmarks are the point of the document, a desktop tool is the honest answer — and it keeps the file on your machine, which a paid web service does not.
Scanned documents, in the order a scanner gives them to you
Sheet-fed scanners produce a file per batch, named scan-1.pdf … scan-10.pdf, and dragging ten rows into order is tedious on a laptop and impossible on a phone. Two things here handle it: A → Z sorts numerically, so scan-2 comes before scan-10 rather than after it, and the ▲▼ buttons on each row work on touch, which the drag handle cannot.
If a batch came out sideways, set that file's Rotate to 90° instead of re-scanning. The rotation is added to whatever the page already carried, so a page already turned 90° and set to 90° here finishes at 180°.