Job portals and applicant tracking systems often cap uploads at 2–5 MB, and some reject an oversized file silently — so you never learn your certificate didn't go through. Compress your CV, certificates, and references before uploading, and do it privately, since these documents carry your personal details.
Why job portals are so strict
Many applicant tracking systems cap each upload at 2–5 MB, and some quietly discard a too-large file rather than warning you. Scanned degree certificates, reference letters, and signed forms are usually the culprits, because they're images of paper rather than digital text.
Compress to "readable on a screen"
A recruiter views your document on a monitor, not at print resolution — so compress to the smallest size that's still comfortably readable. Compress PDF does this in your browser, and a scanned certificate often drops from several megabytes to under one.
Read it before you submit
Open the compressed file and check that a stamp, signature, or small-print clause is still legible. This is your application — thirty seconds of checking is the cheapest insurance there is.
One file, if the portal wants one
If the form asks for a single file (CV + cover letter + references), Merge PDF them first, then compress the result. Starting from a Word CV? Word to PDF gives you a clean, watermark-free PDF to submit.
Why privacy matters here specifically
Your CV has your address, phone number, and full history; certificates may carry ID numbers. Because these tools run on your own device, none of it is uploaded to a conversion server — which is exactly what you want for documents this personal. If it's still over the limit after compressing, extract only the required pages with Split PDF.
What most portals actually accept
Application portals commonly cap uploads between 2 MB and 5 MB, and a surprising number reject an oversized file without saying why — the upload simply fails or the field silently clears. Assume the lower end unless the form states otherwise, and check the file size before you start rather than after the third failed submission.
Why your CV is large in the first place
A CV written in Word and exported to PDF is usually well under 500 KB, because it is mostly text. If yours is several megabytes, something in it is an image: a scanned signature, a photo, a certificate you photographed rather than exported, or a design template with a full-page background. That image is essentially the whole file, and it is what compression acts on.
Which is also why compressing a text-only CV does almost nothing: there is nothing large to shrink. If a plain CV is somehow enormous, it was probably produced by scanning a printed copy, and the right fix is to export a fresh PDF from the original document rather than to compress a photograph of it.
Check it still reads before you send
Open the compressed file at 100% and look at the smallest text and any logo. Compression trades resolution for size, and the point where a scanned certificate stops being legible arrives sooner than most people expect. If it looks soft, compress less and remove pages you do not need instead.