How to combine scanned pages into a single pdf
- Step 1Scan or collect each page as a PDF — Scan each page with your device. If your scanner outputs images (JPG, PNG, TIFF) rather than PDFs, convert them first with Image to PDF — each image becomes one PDF page, ready to merge.
- Step 2Check the page order before loading — The merge panel combines files in the order you add them and has no drag-to-reorder. Sort your scans by filename (most scanners number sequentially, e.g.
scan_001…scan_010) so you can load them in correct page order. - Step 3Drop the page scans into the merger — Add the scans to PDF Merge in page order. Each tile shows its size and page count. To fix a mis-ordered page, click × to remove and re-add it in the right place.
- Step 4Run the merge — With at least two scans queued, click Process. The engine appends each scanned page into one new PDF, locally — the original image bytes are embedded unchanged.
- Step 5Straighten or rotate any crooked pages — Merging does not deskew or auto-rotate. If a page came in sideways or upside-down, fix it with PDF Rotate on the merged file (you can target specific pages).
- Step 6Add OCR if you need a searchable document — The merged scan is still image-only. To make it searchable and copyable, run PDF OCR afterward — it adds an invisible text layer over the scanned images.
What merging does and doesn't do to scans
Scanned pages are images. Merging assembles them; it does not process the image content. Grounded in the actual page-copy behaviour.
| Operation | Does merge do it? | How to get it |
|---|---|---|
| Combine pages into one PDF | Yes — that's the whole job | This tool |
| Keep original scan resolution | Yes — images embed unchanged | Automatic; no recompression |
| OCR / make text searchable | No — output stays image-only | PDF OCR after merging |
| Deskew / straighten crooked pages | No | Re-scan, or rotate with PDF Rotate |
| Rotate sideways/upside-down pages | No — orientation is kept as captured | PDF Rotate |
| Reorder pages | No drag-to-reorder — load order is page order | PDF Reorder after merging |
| Reduce file size of big color scans | No | PDF Compress (Aggressive) |
Handling each scanner output format
What your device produces and the route to a merged PDF.
| Scanner output | Route to merge | Searchable? |
|---|---|---|
| One PDF per page | Merge directly | Only if the scanner embedded text (OCR'd PDF) |
| JPG / PNG per page | Image to PDF → merge | No — run PDF OCR after |
| TIFF per page | Convert to PDF/JPG first, then merge | No — OCR after |
| Multi-page PDF already | No merge needed (unless joining several) | Depends on scanner settings |
| Scanner with built-in OCR (searchable PDF) | Merge directly — text layer is preserved per page | Yes — copied as-is |
Cookbook
Common scan-stitching jobs. Load order is page order, so each example lists the exact sequence.
Stitch a 10-page scan saved as one file per page
The classic flatbed/MFP output. Sort by the scanner's sequential numbering, then load in order.
Files: scan_001.pdf … scan_010.pdf (each 1 page) Load order: scan_001, scan_002, … scan_010 Merged: scan_001.merge.pdf — 10 pages in order. Still image-only — run PDF OCR if you need search.
Phone-scanned receipts saved as JPGs
A scanner app exported JPGs, not PDFs. Convert first, then merge.
Step 1: Image to PDF on receipt1.jpg, receipt2.jpg, receipt3.jpg
→ three single-page PDFs (image embedded at full res)
Step 2: Merge the three PDFs in date order
Result: one receipts PDF for an expense claim.Fix an upside-down page after merging
Page 4 was fed into the scanner the wrong way. Merge first, then rotate just that page.
Step 1: Merge scan_001…scan_006 → doc.merge.pdf
Step 2: PDF Rotate, angle 180, pages "4"
→ page 4 corrected, rest untouched
Merge does not auto-rotate; rotation is a separate step.Make a stitched scan searchable
The merged contract scan needs to be findable and copyable. Add an OCR text layer.
Step 1: Merge the page scans → contract_scan.merge.pdf (image-only)
Step 2: PDF OCR, language English
→ invisible text layer added over each page
Now Ctrl+F finds words; the images are unchanged.Shrink huge color scans before merging on free tier
300-DPI color scans can be several MB each — over the 2 MB free cap. Compress, then merge.
Each scan ≈ 3.5 MB (over free 2 MB limit) Step 1: PDF Compress (Aggressive), target 1.5 MB, per file Step 2: Merge the compressed scans Trade-off: aggressive compression re-encodes the page image (lower quality) to hit the size — acceptable for archival scans.
Edge cases and what actually happens
You expected merging to make the scan searchable
No OCRMerging only assembles pages — it does not run OCR, so the combined file is image-only and Ctrl+F finds nothing (unless your scanner already embedded a text layer). To add search, run PDF OCR on the merged document; it overlays an invisible, selectable text layer without altering the scan images.
A page is crooked or skewed
Not correctedMerge does not deskew — a crooked scan stays crooked in the output. There is no straightening step in this tool; re-scan the page flat, or accept minor skew. (For full 90°/180°/270° orientation fixes, use PDF Rotate; it rotates in quarter turns, not arbitrary skew angles.)
A page came in sideways or upside-down
Not correctedOrientation is preserved exactly as captured — merge won't auto-rotate. Fix it as a separate step with PDF Rotate on the merged file, targeting just the affected page numbers (e.g. 90° for sideways, 180° for upside-down).
Your scanner outputs TIFF or JPG, not PDF
Convert firstThe merger accepts PDFs; image files must be converted first. Use Image to PDF for JPG/PNG (each becomes one page at full resolution), then merge. TIFFs should be converted to PDF/JPG first as well — TIFF isn't a direct input here.
Pages merged in the wrong order
By designFiles combine in load order with no drag-to-reorder. Sort scans by filename before loading, remove and re-add any misplaced page, or rearrange the merged result with PDF Reorder by entering the correct page sequence.
Color scans exceed the 2 MB free limit
Limit reachedHigh-DPI color scans often top 2 MB per file, which the free tier blocks. Reduce size first with PDF Compress (Aggressive) (optionally to a target size), or upgrade to Pro (50 MB / 500 pages per file).
More than 2 scanned pages on free tier
Limit reachedFree merging handles 2 files per batch, once a day — a multi-page scan saved as one-file-per-page can exceed that fast. Either merge in passes of two (combine 1+2, then add 3+4…), use Image to PDF to build a multi-page PDF from images in one step, or upgrade to Pro for unlimited files.
Duplicate or blank scanned pages
Not removedMerge does not detect duplicates or blank pages — it appends everything you load. Remove unwanted pages from the merged file with PDF Delete Pages, specifying the page numbers to drop.
Frequently asked questions
Does merging scanned pages make them searchable?
No. Merging assembles image pages into one PDF but does not run OCR, so the result is image-only and not text-searchable — unless your scanner already produced searchable (OCR'd) PDFs, in which case that text layer is preserved. To add search to image-only scans, run PDF OCR on the merged file; it overlays an invisible, selectable text layer.
Will merging reduce the quality of my scans?
No. Each scanned page is embedded exactly as captured — no recompression or downscaling — so resolution, signatures, and fine print are preserved. Quality only changes if you deliberately run a scan through PDF Compress (Aggressive) to reduce file size.
Can I merge JPG or PNG scans directly?
Not directly — the merger takes PDFs. Convert images to PDF first with Image to PDF, where each image becomes one page at full resolution, then merge the resulting PDFs. If all your scans are images, Image to PDF can build a multi-page PDF in a single step without a separate merge.
My scanner saves as TIFF — will that work?
Not as a direct input. Convert the TIFF pages to PDF (or JPG, then via Image to PDF) first, then merge the PDFs here. The merger's accepted input is PDF; TIFF must be converted upstream.
Can I reorder the scanned pages before merging?
There is no drag-to-reorder in the merge panel — pages combine in the order you add them. Sort your scans by filename (most scanners number sequentially) and load them in page order. If a page lands wrong, remove and re-add it, or fix the sequence afterward with PDF Reorder.
Will the tool straighten crooked or skewed scans?
No. Merging does not deskew or adjust image content — a crooked page stays crooked. For orientation problems (sideways or upside-down), use PDF Rotate on the merged file, which rotates in 90° increments. There is no arbitrary-angle deskew; for badly skewed pages, re-scanning flat is the reliable fix.
How do I fix one upside-down page in the merged document?
Merge first, then use PDF Rotate and target just that page number with a 180° rotation (or 90° for a sideways page). Merging preserves each page's orientation as captured, so rotation is a deliberate, separate step you control.
How many scanned pages can I merge at once?
Free merging combines 2 files per batch, once per day, with each file up to 2 MB and 50 pages. For a long scan saved as one-file-per-page, either merge in passes of two, build a multi-page PDF from images with Image to PDF, or upgrade to Pro for unlimited files at 50 MB / 500 pages each.
Are my scanned documents uploaded anywhere?
No. The merge runs entirely in your browser using pdf-lib; scanned IDs, contracts, medical records, and other sensitive images never leave your device. Only an anonymous run counter (no content) is recorded when signed in, and you can opt out.
Can I remove a blank or duplicate scanned page?
The merge appends every page you load and doesn't detect blanks or duplicates. After merging, drop unwanted pages with PDF Delete Pages by entering their page numbers — the original scans are never modified.
My color scans are too big for the free limit — what can I do?
High-DPI color scans frequently exceed the 2 MB free per-file cap. Compress them first with PDF Compress (Aggressive) — you can target a specific size like 1.5 MB — then merge. This re-encodes the page image (some quality loss), which is usually acceptable for archival scans. Pro raises the limit to 50 MB per file.
If I have a scanner that already does OCR, is the text kept?
Yes. If each input PDF is a searchable (OCR'd) scan, the existing text layer is copied along with the page image during the merge, so the combined file stays searchable. Merge never removes a text layer — it just doesn't add one to image-only scans.
Privacy first
All PDF processing runs locally in your browser using PDF-lib and pdf.js. No file is ever uploaded — only metadata counters are saved for signed-in dashboard stats.