Check your PDF before you upload it: ten quick checks

The short answer: open it, then check these ten things

Open the file in the PDF viewer, which runs in your browser and never changes or saves your file. Then go through the list:

1. Right file? Names like final2-new.pdf lie. Open it and look.
2. All pages there? Count them against what the form needs.
3. In the right order?
4. All upright?
5. Readable at normal zoom? Names, dates, numbers and seals.
6. Whole page in the picture, with no cut-off edges?
7. Opens without a password?
8. Under the size limit?
9. Searchable text, or a scan? Know which, if the form cares.
10. A clear file name that follows the form's rules.

The sections below show how to check each one in the viewer and which tool fixes it when it fails. The form's own notice always wins over this post: sizes, formats and names differ from portal to portal.

What goes wrong, and why you find out too late

A portal usually tells you only that something failed, or nothing at all until a person looks at your file days later. The usual causes are simple, and all can be seen in a minute:

• A page is missing, doubled, or in the wrong place.
• A page is sideways or upside down. Your phone showed it upright, but the file isn't.
• The text is too small or soft to read after the file was shrunk.
• The file needs a password to open, so the portal can't read it.
• The file is a little over the size limit.
• It is the wrong version of the file.

The viewer is made for this. It opens a PDF straight from your device in a second or two, so you can look at it the way the person receiving it will. A scan of 42 pages and 47.8 MB showed its first page in 0.4 to 1.6 seconds in our own tests, run in headless Chromium at computer size, and a 400-page scan in 0.7 to 1.5 seconds. Phones are usually slower, and these tests don't cover Safari or Firefox.

How to check each one in the viewer

A few viewer tips make this quick. The page box lets you type a number and press Enter to jump there. Zoom goes from 25% up to 400%, and the zoom menu offers Fit width, where every PDF starts, and Fit page, which shows a whole page at once. On a computer, the arrow keys move between pages and Home and End go to the first and last page.

Doing the check on a phone

Most uploads are done from a phone, so check on the phone you'll upload from. Open the viewer in Chrome on Android, or Safari or Chrome on iPhone, tap Open a PDF and pick the file, for example from Downloads or the Files app. Then:

• Turn the phone sideways for bigger text. At Fit width, the pages grow to fill the wider screen.
• Zoom with the plus button for sharp text. Pinching enlarges the page as a picture, so small text can look soft. The plus button draws the page again, sharp, at the new size.
• Swipe up and down to read. When a page is zoomed wider than the screen, swipe sideways.
• Jump with the page box: tap the page number, type the page and press Go.
• The side panel slides in over the pages and closes when you pick a page.

If a very big scan makes your browser slow, close other tabs and apps, and read at Fit width rather than a high zoom. How to open a large PDF file without it freezing has more.

Searchable text, or a scan: why it can matter

Some PDFs hold real text, like a certificate downloaded from a portal or a letter saved from Word. Others hold only pictures of pages, like anything scanned or photographed. To tell, press the magnifier, or Ctrl+F on a computer, and search for a word you can see on the page. If the viewer marks it in yellow, the file has text. If the count says No text and a note says the file is most likely a scan, every page is a picture. You can also try to select a line of text: if no words get selected, the page is a picture.

For most uploads, a scan is fine. An officer reads it with their eyes. But a few places ask for a "searchable" or "text" PDF. Our tools do not do text recognition (OCR), so a scan stays a picture. If a form needs real text, use the original typed file, or a program that can run text recognition on the scan.

One more benefit: a text PDF is usually far smaller than a scan. A typed one-page form was 33 KB in our tests. Check the post How to search a word in a PDF and fix search not working if search finds nothing in a file that should have text.

Size limit and file name

The viewer doesn't show the file size, but your file manager does. Compare it with the form's limit. "Under 200 KB" in our tools means at most 200,000 bytes, which a file app that counts 1,024 bytes to a KB shows as about 195 KB, so the file is under the limit whichever way the portal counts. If it's over:

• An exact limit: Compress PDF to 100 KB, 200 KB, or Resize PDF for any size. See PDF to 500 KB, 1 MB or 2 MB for visa and admission forms.
• Photos of papers: Photo to PDF under 100 KB for online forms goes from photo to upload.
• A whole set: Job form documents under 100 KB and Combine resume, cover letter and certificates in one PDF.

Shrink last, then open the shrunk file in the viewer and check the smallest text again. The limit is checked on the very file you upload.

For the file name, follow the form. Where it doesn't say, a short, clear name with letters, digits and dashes, like Priya-Sharma-marksheet-12.pdf, is the safest. Some portals dislike long names or unusual symbols. Don't put your ID number in the name.

If a check fails: which tool fixes it

After any fix, open the new file in the viewer and run the checks again. That takes a minute and avoids a second rejection.

What the viewer can't tell you

• Whether the portal will accept it. Only the form's notice knows its rules. Check the size, the format and the number of pages it asks for.
• Whether a digital signature is valid. A signed PDF shows its pages, but the viewer can't check the signature.
• Form fields. They show as saved, but you can't type in them or tick boxes. Fill in the form in your usual reader, then check it here.
• Printing. The viewer doesn't print. Open the file in your device's PDF app or browser viewer.
• Editing. The file is never changed. It only reads.

A final tip: if the portal says "file corrupt" or "unreadable," the usual causes are a password, damage from an incomplete download, or a size over the limit. The viewer tells you the first two in seconds. A file that can't be opened shows "This file can't be opened." Download it again from where you got it.

Check your papers without sharing them

The files you check before an upload are ID cards, marksheets and bank papers. Some online viewers send the file to their server first. Ours doesn't: your browser reads the file from your device and draws the pages itself, and the viewer keeps no copy of your file, your searches or the names of files you opened. The page contacts only this site and Google's ad service, which shows the ads that keep the tools free, and our code never gives your files to the ad code. The privacy policy has the details.