Compress PDF
Reduce file size while optimizing for maximal PDF quality.
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 reduces your PDF file size without sacrificing readability. Whether you need to email a document, upload it to a portal with file-size limits, or simply free up storage, this tool delivers meaningful compression in seconds.
Three compression levels give you full control: Extreme achieves the smallest possible file size (ideal for archiving), Recommended balances quality and size reduction for everyday sharing, and Less Compression keeps the visual quality nearly identical while still trimming unnecessary metadata and redundant data.
- check_circleThree compression levels: Extreme, Recommended, Less
- check_circleRemoves hidden metadata and redundant object streams
- check_circleText and vector graphics remain crisp and searchable
- check_circleHandles PDFs up to 50 MB — all pages compressed at once
- check_circleNo watermark added to output file
- check_circle100% browser-based — nothing installed on your computer
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? expand_more
Yes. Switch to Target file size, type the size you want (for example 100 KB or 1 MB), 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.
How much can I reduce PDF file size? expand_more
Results vary by content. PDFs with large embedded images typically see 40–70% size reduction on the Extreme setting. Documents that are already well-optimised or contain mostly vector graphics may reduce by 5–15%.
Will compression make my PDF look blurry? expand_more
On the Recommended and Less Compression settings, visually there is no noticeable difference. Extreme compression reduces image resolution, which may affect PDFs with high-resolution photos.
Is there a file size limit for PDF compression? expand_more
Yes, the maximum file size per upload is 50 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? expand_more
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? expand_more
Yes. JustConvert compresses image streams within the PDF but does not alter the text layer. All text remains selectable and searchable after compression.