Compress PDF – Reduce PDF Size
Free PDF compressor: enter a target like 100 KB or 1 MB and download a smaller PDF that still reads clearly.
How it works
Select PDF
Choose a file from your computer or drag it into the upload box.
Enter target size
Type the size you want in KB or MB, for example 100 KB.
Download
We compress as close to your choice as possible and the optimized file is ready to download.
About This Tool
JustConvert's PDF compressor, also called a PDF size reducer, shrinks a PDF to the size you choose. Type a target such as 100 KB, 200 KB or 2 MB and the tool compresses the file as close to that number as it can, so it fits an upload portal, an exam or government form, or an email attachment limit.
Compression runs on our server. The tool first removes unused data, then lowers the resolution and quality of embedded images step by step until the file reaches your target. Text stays selectable and searchable, no watermark is added, and the uploaded file is deleted as soon as processing finishes.
- Compress to an exact size in KB or MB
- Removes hidden metadata and unused objects
- Text stays sharp, selectable, and searchable
- Handles PDFs up to 150 MB
- No watermark added to the output
- Works on phone and desktop, nothing to install
What actually makes a PDF large
Before compressing, it helps to know where the weight is. In most PDFs the size comes from embedded images — scans, photos, and screenshots stored at full camera resolution. A single phone photo can outweigh a hundred pages of text. Text and vector graphics, by contrast, are tiny. That is why a 10-page scanned document is often far heavier than a 200-page text report. Good compression targets the images and leaves the text layer alone, which is exactly how this tool behaves.
How the compression actually works
JustConvert reduces size in two stages. First it strips invisible bulk: duplicated objects, unused resources, and leftover metadata that add nothing to what you see on screen. This alone shrinks many files with zero visible change. Second, for bigger savings, it downsamples and re-encodes images — lowering their stored resolution and tightening JPEG compression until the file approaches the size you asked for. Throughout, the text stays selectable and searchable, so the document remains copy-paste friendly afterwards.
Choosing the right target size
If a portal hands you a number, aim straight for it using the target-size box above. These are the limits worth knowing so you do not over-compress and lose quality you did not need to:
Common upload limits and what target to choose
| Where you are uploading | Typical size limit | What to set |
|---|---|---|
| Email attachment (Gmail, Outlook) | 20–25 MB | No aggressive target needed; most files already fit |
| Government / exam form uploads (India) | 100–500 KB | Set a small KB target; expect lower image detail |
| Job portals and résumé uploads | 1–2 MB | A 1–2 MB target keeps text and logos crisp |
| Visa / passport document portals | 250 KB – 1 MB | Compress photo pages hard, keep text pages readable |
When a target can't be reached, and other limits
Very small targets are not always physically possible. A page that is essentially a high-detail photograph can only shrink so far before the text on it becomes unreadable. If you ask for 50 KB on an image-heavy scan, you may receive the smallest version achievable along with a note that the exact target was missed — raise the target slightly if readability matters more than the last few kilobytes. For a long scan that must hit a tiny limit, it often helps to keep clean text pages light and only compress the genuinely photographic pages aggressively.
Two things compression cannot do: it will not shrink a password-protected PDF until the password is removed first, and it will never sharpen a blurry scan — it can only make files smaller, not clearer. If a file is already well optimised, expect a modest 5–15% reduction rather than a dramatic one.
Frequently Asked Questions
Can I compress a PDF to a specific size like 100 KB?
Yes. Type the size you want (for example 100 KB or 1 MB) in the target box and we compress as close to that target as possible. If the file already fits, the text layer is kept; for smaller targets we reduce image quality to reach the size. If a target is physically too small, you get the smallest version we can produce and a note that it could not be reached.
Is this the same as a PDF size reducer or PDF KB reducer?
Yes. Compress PDF, PDF compressor, PDF size reducer, and PDF KB reducer all describe the same job: making a PDF file smaller. Here you choose the exact size you need in KB or MB.
How much can I reduce PDF file size?
Results depend on what is inside the file. Scanned PDFs and PDFs with large photos usually shrink by 60–90%. Documents that are mostly text are already small and may shrink by only 5–15%.
Will compression make my PDF look blurry?
At moderate targets there is no visible difference. Very small targets, such as 50 KB for a multi-page scan, lower image resolution, so photos and scanned pages look softer. If the result is hard to read, compress the original again with a slightly larger target.
Is there a file size limit for PDF compression?
Yes, the maximum file size per upload is 150 MB. If your file exceeds this, try splitting it first using our Split PDF tool and then compressing each part.
Does compressing a PDF remove passwords or encryption?
No. Password-protected PDFs cannot be compressed directly. Use the Unlock PDF tool to remove the password first, compress the file, and then re-protect it if needed.
Is the compressed PDF searchable and copy-paste friendly?
Yes. JustConvert compresses image streams within the PDF but does not alter the text layer. All text remains selectable and searchable after compression.