“File Is Too Large” When Uploading a PDF: Every Fix, in Order

Step 0: find out exactly how far over you are

Right-click the file and open its properties (Get Info on a Mac) to see the size in bytes. Then read the portal's instructions for both a maximum and a minimum. Government portals often set both. The UPSC One Time Registration FAQ, for example, asks for the photo identity card as a PDF of no more than 300 KB and no less than 20 KB. A file squeezed to 15 KB gets rejected just like one at 400 KB.

Also check which kind of kilobyte you are aiming at. The TryDocsy compressor counts 1 KB as 1,024 bytes, so a 300 KB target means at most 307,200 bytes. If a portal counts 1 KB as 1,000 bytes, set your target a little lower, such as 290 KB, to leave room.

Our test file

To make the numbers below meaningful we built the kind of file that usually causes trouble: one typed text page, two A4 pages scanned at 300 DPI (one colour, one grayscale), and two full-page 3840 × 2400 photos, the sort of thing people add when they photograph a certificate on a phone. The finished PDF was 3,923,446 bytes (3.74 MB), five pages.

Fix 1: remove pages the portal didn't ask for

This is the only fix that costs no quality at all. People often upload a whole scanned bundle when the form wants one document, or include a blank back side from a duplex scan. Open Delete Pages, click the pages to drop or type them into the Pages to delete box (for example 4-5), and download the rest. Removing our two photo pages cut the file from 3.92 MB to 1.49 MB, and the typed page kept its selectable text.

Removing pages also helps if you still have to compress afterwards. A fixed byte budget spread over fewer pages means each page gets more of it. Our three remaining pages fit into 101,514 bytes, about 34 KB per page, against about 19 KB per page when all five were squeezed to the same target.

Fix 2: split the file if the form accepts several uploads

Some forms have separate slots for each certificate, or let you add more than one attachment. In that case, Split PDF the bundle by page ranges (such as 1-2, 3, 4-5) or every N pages, and upload each part into its own slot. Every part stays at original quality, which matters for anything a reviewer must read closely, such as a mark sheet.

Fix 3: compress to the exact limit

When the pages all need to be there and the file must still shrink, compression does the heavy lifting. On the compress page choose Target Size, pick a preset (50 KB up to 10 MB) or type your own number, and press Compress. The tool tries several JPEG quality levels, up to eight rounds, and keeps the best result that fits under your number.

• The target is a ceiling, not a goal. Our 2 MB and 1 MB targets both produced about 536 KB, because the highest quality the tool uses already fit. That is normal.
• The compressor redraws every page as a picture. Text in the output can't be selected, searched or copied, and page dimensions in the output are larger than A4 (833 × 1179 points in our test), even though everything scales to fit on screen. If a portal needs searchable text, compress the scan before making it searchable, not after.
• Target-size mode is slower than the quality slider: 30 to 50 seconds for our five pages. The tool stops with “Compression timed out” after 90 seconds, so keep the tab open and in front while it works, and remove or split pages first for long documents.
• If no quality level fits, you'll see “Could not reach target” with the best size it managed. Delete pages or split the file, then try again.

Grayscale: helpful for printing, unhelpful before compressing

Converting to black and white sounds like an easy size win, and it can be on its own: our file dropped to 827,632 bytes at the 144 DPI setting of Grayscale PDF and 250,704 bytes at 72 DPI. But that tool also redraws each page as an image, at double the page dimensions for the 2x setting. When we then asked the compressor for 100 KB, the larger pages could not get under the limit and the best it managed was 113,146 bytes. Compressing the original directly reached 93,758.

So pick one or the other. Use Compress PDF with a target when the goal is an upload limit. Use grayscale when the goal is a black-and-white document for printing or a portal that explicitly asks for grayscale scans.

Fix 4: rescan smaller at the source

If you still have the paper, a better scan beats any amount of compression afterwards. Scanner apps often default to 300 or 600 DPI in colour, far more than an on-screen reviewer needs. In a separate test for our OCR guide, the same A4 notice saved as a single-page PDF took 578,802 bytes at 300 DPI in colour and 171,037 bytes at 150 DPI, before any compression.

1. Choose grayscale unless the document has colour that matters, such as a stamp or a photo.
2. Use 150 to 200 DPI for typed documents. Go no lower than 150 if the text is small.
3. Crop to the page edge so the scanner bed and shadows aren't stored.
4. Save as PDF directly from the scanner app, or scan to JPG and combine the images into a PDF.

Still rejected? Check these

• Below the minimum: if the portal also sets a lower limit (20 KB is common), a very aggressive target can undershoot it. Pick a target comfortably above the minimum.
• Wrong file type: some forms want JPG for photos and PDF for documents. A PDF renamed to .jpg won't pass.
• Password protection: an encrypted PDF often fails silently on portals. Remove the password before uploading.
• File name: long names with symbols or spaces trip up some older systems. Rename to something simple like idproof.pdf.

Frequently asked questions