Key takeaways
- Check the exact size limit first, then shrink in small steps: Recommended, then Smaller, then Smallest only if you must.
- Removing pages you do not need and shrinking big photos before they go into the PDF often saves more than compression alone.
- Smallest turns pages into pictures, so keep your original and do not use it when the text must stay selectable.
- Compress PDF runs in your browser, so a private document is not uploaded.
Why PDFs get rejected for size
Email services, job portals, scholarship forms and government sites often set a maximum size for attachments. Phone cameras and scanner apps create large pictures, and a PDF made from them can be many times bigger than the limit. The fix is not to retype anything. You make the file lighter without changing what it says.
Before you do anything, find the real limit. It is usually written next to the upload button or in the instructions. Then check the size of your file in its properties so you know how far you have to go.
The step-by-step method: shrink in small steps
Do not jump straight to the strongest setting. Each step costs some quality, so stop as soon as you are under the limit.
- Open Compress PDF and add your file.
- Start with Recommended. It makes the file smaller and keeps text sharp.
- Check the size of the result. If it is still too big, run the original again with Smaller, which compresses the pictures harder while keeping text sharp.
- Only if you are still over the limit, use Smallest. It turns every page into a picture for the lowest size, so the text can no longer be selected or searched.
- Open the final file and scroll through it before you upload it.
What to do before you compress
The biggest savings often come from changing what goes into the PDF, not from the compression step itself.
- Remove pages you do not need. A blank back page or a cover sheet still takes space. Use Delete PDF Pages.
- Shrink photos before making the PDF. If the PDF is built from phone photos, reduce them first with Compress Image and then combine them with Image to PDF.
- Send only the pages that are asked for. Split PDF pulls out just those pages.
- Scan sensibly. A scan at a very high resolution makes a heavy file. A moderate resolution is enough for reading on screen.
Which tactic helps most
| Situation | Best first move |
|---|---|
| PDF made of phone photos | Shrink the photos, then rebuild the PDF |
| Long scanned document | Compress with Smaller, delete blank pages |
| Mostly text, already small | Little to gain. Check whether it really is over the limit |
| Portal allows several files | Split into parts and upload each one |
| Over the limit by a small amount | Recommended or Smaller is often enough |
A PDF that is mostly text is already compact, so compression may barely change it. Large pictures and scans are where the savings are.
Mistakes that cost people time
- Choosing the strongest level first and ending up with blurry pages.
- Compressing the same file again and again.
- Deleting the original, then needing selectable text later.
- Uploading without opening the final file, and sending a page in the wrong order.
If you are working with sensitive papers such as ID copies or contracts, also read Are online PDF tools safe? so you know how to check that a tool does not upload your file.
Check the result before you send it
Open the compressed file. Zoom in on small print, stamps and signatures. Confirm the page count and order. Look at the file size once more. If everything is readable and under the limit, you are done. If the text became too soft, go back one level and try other ways to reduce the size, such as deleting pages.
Frequently asked questions
Which compression level should I choose?
Start with Recommended. If the file is still too large, try Smaller. Use Smallest only when size matters more than selectable text.
Can I choose an exact file size?
No. The tool offers three levels, not a target size. Try the levels in order and check the result.
Why is my compressed PDF still too big?
PDFs full of large photos or scans may need more than one step. Delete pages you do not need, shrink the photos first, or split the file into parts.
Will compressing change the way my PDF looks?
On Recommended and Smaller, text stays sharp and only pictures are compressed more. On Smallest, pages become pictures.
Is it safe to compress an ID copy or a contract here?
The work happens in your browser and the file is not uploaded to Toolkitties, so it suits private documents.