How to combine multiple scanned images into a single pdf
- Step 1Export each page as JPG or PNG from your scanner app — In your phone scanner or flatbed software, save (or export) each page as a separate
.jpgor.png. PDF-direct exports from the app are already PDFs — bring those to PDF Merge instead. This tool is specifically for image files. - Step 2Open the Image to PDF converter — Go to Image to PDF. It accepts
.jpg,.jpeg, and.png— the formats scanner apps export. TIFF and HEIC are not accepted; convert those to JPG/PNG first. - Step 3Add the scans in page order — Drag the page-images in, ideally one batch in numeric order. Because there is no reorder control, the add order is the final order. If your file picker sorts
scan_10beforescan_2, add them individually in the correct sequence. - Step 4Verify the queue before processing — Each queued scan shows its name and size. Confirm the sequence reads top-to-bottom as the pages should appear. Remove any stray or duplicate scan with the X button. You need at least two files for the Process button to enable.
- Step 5Process to assemble the PDF — The converter adds one page per scan at the scan's pixel dimensions — no resizing, fitting, or compression. A consistent scanner DPI gives consistent page sizes across the document.
- Step 6Download, then OCR if needed — Download the assembled PDF. To make a scanned text document searchable and selectable, run PDF OCR on it; to shrink a heavy scan PDF for upload, run PDF Compress (Aggressive).
Scan source vs. what to do here
This tool only assembles image files. If your scanner already produces PDFs, use a different tool.
| Your scanner produces | Right tool | Why |
|---|---|---|
| One JPG/PNG per page | Image to PDF (this tool) | Stacks page-images into a single PDF, one page each |
| A PDF per page | PDF Merge | Joins existing PDFs; this tool only takes images |
| One multi-page PDF already | Nothing — it's done | Optionally OCR or compress it |
| TIFF scans | Convert to JPG/PNG first | TIFF is not an accepted input format here |
| A scan that is upside-down | Convert here, then PDF Rotate | There is no in-tool rotation |
Scan resolution and resulting page size
Page dimensions equal the scan's pixel dimensions (1 px = 1 pt). Consistent scanner DPI gives consistent page sizes.
| Scan DPI | A4-sized scan pixels (approx) | Resulting PDF page (points) |
|---|---|---|
| 150 DPI | 1240 x 1754 | 1240 x 1754 pt |
| 200 DPI | 1654 x 2339 | 1654 x 2339 pt |
| 300 DPI | 2480 x 3508 | 2480 x 3508 pt |
| 600 DPI | 4960 x 7016 | 4960 x 7016 pt (large file — watch the 2 MB Free cap) |
Cookbook
Typical scanning workflows and the exact PDF they produce. Everything runs locally — document scans are never uploaded.
A six-page contract scanned page-by-page
A flatbed scan of a signed contract saved as six JPGs. Add them in order 1–6 so the contract reads correctly, then OCR to make clauses searchable.
Input (added in order): contract_p1.jpg ... contract_p6.jpg (300 DPI) Step 1 image-to-pdf -> contract.image-to-pdf.pdf (6 pages) Step 2 pdf-ocr (eng) -> searchable text layer added Result: a single searchable contract PDF.
File-picker sorted scan_10 before scan_2
A classic ordering trap. Selecting 12 scans in one file-picker action can sort lexically (scan_1, scan_10, scan_11, scan_2...). Since add order = page order, the PDF comes out scrambled.
Picker order (lexical): scan_1, scan_10, scan_11, scan_12, scan_2, scan_3 ... Resulting page order: WRONG Fix: rename to zero-padded (scan_01..scan_12) OR add files individually in numeric sequence.
Mixed JPG + PNG scans in one document
Some apps export the cover page as PNG and the rest as JPG. Both are accepted and can be mixed freely in one batch; the tool detects each by MIME type and embeds accordingly.
Input: cover.png (embedPng) page2.jpg (embedJpg) page3.jpg (embedJpg) Output: 3-page PDF, page 1 from PNG, 2-3 from JPG.
Upside-down scan fixed afterwards
There is no rotation option in this tool, so a sideways or upside-down scan must be corrected after assembly. Convert, then rotate only the affected page.
Step 1 image-to-pdf -> doc.image-to-pdf.pdf (page 3 is 180 deg)
Step 2 pdf-rotate, angle 180, pages: 3
-> page 3 corrected, rest untouchedHeavy 600 DPI scans over the Free size cap
High-DPI scans easily exceed 2 MB per file. On Free this blocks the batch. Either scan at a lower DPI, downscale the images, or use Pro.
Add: scan_p1.jpg (3.9 MB, 600 DPI) Result: blocked (Free caps at 2 MB/file) Options: re-scan at 200-300 DPI, downsize the JPGs, or upgrade to Pro (50 MB/file).
Edge cases and what actually happens
Pages out of order after multi-select
By designPage order is strictly the add order; there is no reorder control. A file picker that sorts lexically can place scan_10 before scan_2. Zero-pad filenames (scan_01) or add the scans individually in sequence to guarantee correct paging.
Scanner exported a PDF, not images
Wrong toolIf your scanner produced per-page PDFs, this tool will reject them — it accepts only .jpg, .jpeg, .png. Use PDF Merge to join PDF pages instead.
TIFF scans
RejectedMany flatbeds default to TIFF. TIFF is not an accepted input here and is rejected with an Expected: .jpg .jpeg .png message. Convert TIFF to JPG or PNG first, then assemble.
A single 600 DPI scan over 2 MB on Free
BlockedHigh-resolution scans frequently exceed the 2 MB Free per-file limit and block the batch with an upgrade prompt. Scan at a lower DPI, downscale the image, or upgrade to Pro (50 MB) / Pro + Media (500 MB).
Upside-down or rotated scan
Not handledThere is no rotation option in this converter. Assemble the PDF first, then fix orientation with PDF Rotate on the specific page(s). The tool will not auto-detect or correct skew.
Output not searchable
By designThe assembled PDF is image-only — scanned text is not selectable or searchable. Run PDF OCR afterwards to add a text layer (English plus nine other languages are available).
Only one scan available
BlockedThe tool requires at least two files. With a single scan the Process button is disabled. Add a second image and delete its page afterwards, or this may not be the right workflow for a one-page scan.
Mixed page sizes from inconsistent DPI
ExpectedIf different pages were scanned at different DPI or sizes, the PDF will have mixed page dimensions because each page matches its source image. Re-scan at a consistent DPI, or normalise sizes afterwards with PDF Resize.
Very large multi-page scan batch
CautionAssembling dozens of high-resolution scans holds every image in browser memory at once. On low-RAM devices a very large batch can slow or stall the tab. Split into smaller batches and join the resulting PDFs with PDF Merge.
Frequently asked questions
What image formats can I combine?
JPG/JPEG and PNG only. TIFF, HEIC, and WebP are not accepted — convert them to JPG or PNG first. If your scanner outputs PDFs rather than images, use PDF Merge instead.
Will the PDF look identical to my scans?
Yes. Each scan is embedded at its native resolution with no re-compression, and each page is sized to the scan's pixel dimensions, so the PDF is a faithful 1:1 representation of your images.
How do I keep the pages in the right order?
Add the scans in page order — the add order is the final page order, and there is no drag-to-reorder. Watch for lexical sorting in file pickers (scan_10 before scan_2); zero-pad filenames or add files one at a time to be safe.
Can I make the scanned PDF searchable?
Yes, as a second step. This tool produces an image-only PDF; run PDF OCR on the result to add a searchable, selectable text layer.
Why is my scan PDF so large?
Scans embed uncompressed at full resolution, so high-DPI pages produce a big file. Lower your scanner DPI, or run PDF Compress (Aggressive) on the output and set a target size.
How many scan pages can I combine on the Free tier?
Up to 10 images per job, each up to 2 MB. Pro removes the count cap and raises the per-file limit to 50 MB. A minimum of 2 files is always required.
Can I rotate a sideways scan in the tool?
No — there is no rotation option here. Assemble the PDF first, then use PDF Rotate to fix the orientation of specific pages.
Are my scanned documents uploaded?
No. All processing happens in your browser — 0 bytes are uploaded. Sensitive scans (contracts, IDs, medical forms) stay on your device.
Can I mix JPG and PNG scans in one PDF?
Yes. The tool detects each file by type and embeds JPGs and PNGs together in one document without issue.
What if one scan is corrupt?
A truncated or malformed image makes the embed step throw and the whole run fails rather than producing a partial PDF. Re-save the problem scan in any image viewer and try again.
My scans are different sizes — can I make them uniform?
Convert here first (pages will match each scan's size), then run PDF Resize to normalise all pages to A4, Letter, or a custom size.
Can I automate scan assembly?
Yes on paid tiers. The same image-to-pdf job runs locally via the @jadapps/runner, so a scanner-watch-folder pipeline can assemble PDFs without uploading anything.
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.