How to Combine Documents into One PDF for an Online Application
Updated · PixKB
Many application portals give you one upload box per section (say, "Education documents") and accept a single PDF. If you have a filled form, two certificates and a photo of your ID, they need to become one file, usually under a size limit. Here's the method we use, with the sizes we got on real test files.
Tools for this guide: Merge PDF and images (combines everything and fits a size limit) and JPG to PDF (when all you have is photos). Both run in your browser; nothing is uploaded.
Step 1: Collect the right files
Read the upload instructions once more and list exactly which documents belong in this box. Portals reject or delay applications for missing pages far more often than for blurry ones, but extra pages cost size budget. Collect:
- PDFs you already have (a filled form, a downloaded transcript). Keep them as PDFs; don't print and re-scan them, because that turns crisp text into a heavy picture.
- Paper documents, photographed flat in daylight, the page filling the frame. A phone's document-scan mode (in Google Drive, iPhone Notes or similar) crops and straightens automatically.
- iPhone photos (HEIC) can go in directly; they're converted in the browser.
Step 2: Put them in order and drop unneeded pages
Add everything to merge PDF. Arrange the list in the order the portal names the documents (form first is a safe default). For a multi-page PDF, type the pages you need in its Pages box, for example 1-2 to leave out an instructions page. The counter at the top shows the total page count as you go.
Step 3: Set the size limit
Type the portal's limit (or tap 200 KB, 500 KB, 1 MB, 2 MB) and press Merge. If the merged file fits, you're done: every PDF page was copied unchanged. If it's over, PixKB tells you by how much and asks whether to shrink to fit. Shrinking leaves light pages (typed text) exactly as they were and only compresses heavy pages (scans and photos).
Our test: a 3-page typed application form (5.7 KB), one page of a scanned certificate PDF (6.3 MB in total), a phone photo of a document (2.6 MB) and an iPhone HEIC photo (6.2 MB):
| Limit | Result | What happened |
|---|---|---|
| none | 4.47 MB, 6 pages | everything copied as is |
| 1 MB | 978 KB | form pages untouched and selectable; 3 heavy pages compressed (2136 px) |
| 300 KB | 282 KB | form pages untouched; heavy pages at 1175 px |
If everything is a photo, JPG to PDF does the same in one step: four phone photos (13.8 MB together) became a 902 KB A4 PDF under a 1 MB limit, with a Document mode that whitens paper backgrounds.
Step 4: Check before you upload
- Open the PDF and scroll through every page. Is each one upright, complete and readable at normal zoom?
- Check the size in bytes: Windows: right-click → Properties; Mac: Cmd + I; Android Files app: tap the ⋮ menu → Details; iPhone Files: press and hold → Get Info. Portals vary in how they count KB, so being a few percent under the limit is safest. PixKB already counts strictly (1 KB = 1,000 bytes).
- Name the file clearly, e.g.
Surname_Education_Documents.pdf, if the portal shows file names to reviewers.
Common problems
"This PDF is password-protected." Some bank and university PDFs open with a password. Open it in your PDF reader with the password, then save or print an unprotected copy and use that. PixKB never bypasses protection.
A page appears sideways. Photos taken in landscape become landscape pages, which is usually right for ID cards. If a portrait document came out sideways, rotate the photo in your gallery app before adding it, or use JPG to PDF, which has a rotate button for each page.
It's still over the limit after shrinking. See PDF still too big after compressing. Usually the answer is fewer pages.
Test notes: test documents were generated for testing; processed in Chromium on a laptop; sizes in decimal units (1 KB = 1,000 bytes).
Frequently asked questions
Can I combine a PDF and JPG photos into one file?
Yes. Merge PDF accepts PDFs and images together; each image becomes its own page and PDF pages are copied unchanged.
Will the typed text in my form still be selectable after merging?
Yes. Merging copies PDF pages exactly. Even when you shrink to fit, light pages such as typed forms are kept as they are.
How do I keep only some pages of a long PDF?
Type the pages you want in that file's Pages box, for example 1-3, 5. Leave it empty to keep all pages.
Is it safe to combine ID documents with an online tool?
With PixKB the files never leave your device: merging happens in your browser. Upload-based tools send your documents to their servers, so check their privacy policy first.
What order should the documents be in?
Follow the order the portal lists them in. If it doesn't say, put the application form first, then identity documents, then certificates.