How to reduce a PDF file size for an upload form or email
Updated 2026-09-22
Last checked: 2026-09-20. Verify with the official source before submitting.
Upload forms and email servers cap attachments: Kuwait's PACI photo form, for example, accepts PDF, JPEG, JPG or PNG up to 2 MB, and Gmail sends at most 25 MB of attachments per email. A few pages scanned with a phone easily go past those numbers, because every page is a full-resolution photograph.
This guide explains where the size comes from, shows how to bring a PDF under a limit in your browser with the PDF compressor, and says honestly when a different approach (splitting the file, or exporting it again from the app that made it) gives a better result.
Requirements at a glance
| Requirement | Value | Source |
|---|---|---|
| Example portal limit (Kuwait PACI photo form) | 2 MB; PDF, JPEG, JPG or PNG | services.paci.gov.kw photo form (Arabic) |
| Gmail attachment limit | 25 MB in total; larger files are added as a Google Drive link | Gmail Help |
| Engine used when pages must become images | pdf.js (Mozilla) renders the pages in your browser | pdf.js project |
Open the tool with these settings
Type your limit in KB, or pick a level. Text is kept first; pages become images only if they must.
When one file cannot reach the limit at a readable resolution.
All tools linked here run in your browser; the photo is never uploaded to GivenTool.
Why a PDF gets big
A PDF exported from Word or a web browser stores text as text and is usually tiny: a few hundred kilobytes for a dozen pages. A scanned PDF, or a PDF made from phone photos, stores each page as an image. A phone photo of an A4 page is typically 3000 to 4000 pixels on the long side, so ten pages can reach 20 MB or more.
That is why compressing a scan works so well: the pages are pictures, and pictures can be stored at a lower resolution and a higher JPEG compression without looking different on screen. It is also why a text PDF shrinks much less: its text is already compact, and there are few pictures to make smaller.
Step by step: compress to a limit
Open the PDF compressor and choose your file. Pick "Hit a target file size" and type the limit you were given in KB (1 MB = 1024 KB; if the form says 2 MB, 1950 KB leaves a safety margin in case it counts a megabyte as 1,000,000 bytes).
For scans of printed text, turn on black and white: it often halves the size. Click Compress PDF. The result shows the new size and what was changed. If the pages had to be turned into images to fit, it says so and reports the lowest page resolution that was needed; below about 100 dpi, zoom in and check that small print is still readable before you upload.
If a long document cannot reach the limit at a readable resolution, split it (for example one file per document the portal asks for) or remove pages the portal does not need, then compress each part.
- The compressor keeps the text first: it resamples the pictures inside the PDF, removes duplicate and unused data and recompresses the file, so text stays selectable and links and form fields keep working. Only if that cannot reach your limit are the pages rendered as images with pdf.js, which makes the text unselectable; the result tells you when that happened.
- Keep your original file; the compressed copy is for the upload.
When to use a different method
If the PDF was made from a document (Word, Google Docs, a web page) and you still have the source, export it again: most apps offer a smaller or "online" PDF option. Such PDFs are often compact already, so the compressor may save little; when nothing can be saved it says so and gives you back the original rather than a bigger file.
If the limit is for email rather than a form, remember that Gmail replaces attachments over 25 MB with a Google Drive link automatically; the recipient still gets the file.
Frequently asked questions
Can I compress a PDF without losing quality?
Not by much, if the PDF is a scan: the size is the images, and making them smaller means lower resolution or stronger JPEG compression. The goal is a file that is still clearly readable at the portal's limit, which the compressor checks for you by reporting the resolution it used.
Why did my PDF hardly get smaller?
It was probably a text PDF exported from a word processor. Those are already compact: text takes little space and there are few pictures to shrink. When nothing can be saved, the compressor says so and returns your original unchanged. Only the Maximum mode, which turns pages into images, can make such a file bigger, and it tells you when it does.
Is the PDF uploaded to compress it?
No. The GivenTool PDF compressor runs in your browser; the file stays on your device.
What size should I aim for if the form says 1 MB?
Aim a little lower, such as 950 KB. Some systems count 1 MB as 1,000,000 bytes rather than 1,048,576, and a small margin avoids a rejection.
This guide summarises published requirements for convenience. It is not legal advice and GivenTool is not affiliated with any government. The issuing authority's page is the only authoritative source.
Last checked: 2026-09-20. Verify with the official source before submitting.