The overlooked PDF problem in upload forms: fixed file-size limits

nikoo li — Mon, 06 Jul 2026 02:16:20 +0000

A small product detail I keep running into: upload forms often fail PDFs for a very boring reason.

The file is not broken. The layout is fine. The user just needs the PDF to be under a fixed limit like 10 MB, 20 MB, or 25 MB.

This happens a lot with:

portfolio submissions
school or job applications
client handoff portals
internal forms
support ticket attachments

The usual advice is “compress the PDF,” but that is a bit vague. In practice, the user does not always want maximum compression. They want a specific outcome:

Make this PDF fit under the upload limit, then let me check whether it still looks acceptable.

That is the workflow I built TinyPDF around:

https://tinypdf.cn/?utm_source=devto&utm_medium=developer_promo&utm_campaign=portfolio_upload_limits&utm_content=devto_upload_limit_workflow_20260706

It is intentionally narrow:

Upload one PDF.
Enter the target size in MB.
Download the compressed result.
Open the result and inspect it before submitting.

The interesting product lesson for me is that “PDF compression” is too broad a category. The sharper use case is the moment when an upload form rejects a file and the user has one concrete number to hit.

If you build upload flows, what file-size limits do you usually set for PDFs? And do you explain the limit before or after the upload fails?

Compressing PDFs to a target file size instead of guessing quality presets

nikoo li — Thu, 02 Jul 2026 11:19:40 +0000

When a PDF is too large, the real requirement is often not “make it smaller.”

It is usually more concrete:

the job portal says the file must be under 10 MB
the school form rejects anything above 5 MB
the client upload system has a 20 MB limit
an email attachment fails at the last step

That is why I built TinyPDF as a small target-size PDF compressor:

https://tinypdf.cn/

Instead of choosing “low / medium / high” compression and checking the result manually, the workflow is:

Upload one PDF
Enter the target size in MB
Let the tool try to compress under that limit
Download the result

The implementation goal is to preserve page count, page dimensions, and layout whenever possible. If the PDF is image-heavy and the target is very small, there is always a quality tradeoff, so the UI tries to keep that expectation clear.

This is a narrow tool by design. It does not merge, split, edit, OCR, or sign PDFs. It only focuses on one annoying workflow: “this file needs to be under a specific size.”

I am sharing it here because I would like feedback from people who deal with document uploads in real workflows:

Is target-size compression clearer than quality presets?
What file limits do you see most often?
What privacy details should be visible before upload?

DEV Community: nikoo li

The overlooked PDF problem in upload forms: fixed file-size limits

Compressing PDFs to a target file size instead of guessing quality presets