Tension Free Zone

Compress PDF to a Target Size Free Online

Shrink a PDF locally with balanced or extreme presets, or set an exact target size such as 50 KB or 100 KB. See before and after sizes instantly, no uploads.

What compressing does

Compressing rewrites a PDF so it takes less space: images are downsampled and re-encoded, duplicated fonts are dropped and the file structure is cleaned up. Text stays text, so a compressed document is still searchable, still copyable and still selectable, which is the difference between compressing a PDF and printing it to an image.

Image-heavy scans shrink the most, often by 70 to 90 percent, because a 300 DPI colour scan carries far more detail than a screen needs. A text-only PDF generated by a word processor is already small and barely moves, because there is nothing in it to throw away.

How to compress a PDF

  1. Open the file. The current size and page count appear before anything is processed.
  2. Pick a level, or type the size limit the portal asks for, such as 100 KB or 500 KB.
  3. Compress, and compare the before and after size on screen.
  4. Open the result and read a page before uploading it. A size target that is too aggressive is visible as smeared small print, and portals reject unreadable documents that pass the size check.
  5. Download the compressed copy. The original is left as it was.

A worked example

A four-page admission form is scanned in colour at 300 DPI and arrives as a 2.4 MB PDF. Compressed at a balanced setting it lands near 600 KB, which is fine for email but still over a 200 KB upload limit.

For the 200 KB limit the scan has to give up resolution rather than only quality: downsampling to roughly 150 DPI and converting to greyscale usually lands between 150 KB and 220 KB for a form like this, and the typed fields stay crisp because they were never photographic detail. If the limit is 100 KB on a 300 DPI colour scan, expect to choose between readable text and the limit, and prefer re-scanning in greyscale at 150 DPI over crushing the file.

Mistakes worth avoiding

Picking the smallest possible file and uploading it without opening it. The most common rejection is not "too large", it is a photograph of a signature that is no longer a photograph of a signature.

Compressing an already-compressed file repeatedly. Each pass throws away detail and gains less size than the first.

Expecting a text PDF to shrink dramatically. There are no large images to remove, and the smart move there is usually to reduce embedded fonts or accept the size.

Compressing the only copy. Keep the original until the upload has been accepted.

Where your files go

Nowhere. Compression runs in this tab on your own device, so a document that has your address, your marks or your medical history on it is never sent anywhere to be made smaller.

Frequently asked questions

How do I compress a PDF to under 100 KB?

Pick the exact-size option and type the target, for example 100 KB. The engine downsamples and re-encodes the page images in steps, checks the real output size after each pass, and stops as soon as your file fits.

Which preset should I choose?

Balanced keeps documents readable and is right for essays, forms and reports. Extreme pushes the size down as far as it goes and is meant for strict upload limits, where slightly softer images are an acceptable trade.

Why does my PDF stop shrinking?

Text-heavy files have a floor: embedded fonts, vector art and page structure cannot be discarded without damaging the document, so the tool reports the smallest size it can honestly reach instead of producing an unreadable file. The whole operation runs inside your browser tab; the file is never uploaded, so nothing is stored or logged.

How small can a PDF get?

A scan can usually reach 5 to 10 percent of its original size and stay readable. A text PDF cannot: if it is 80 KB, the floor is close to 80 KB, because its size is the text itself rather than oversized images.

Does compression make text blurry?

No. Text is stored as characters and is rewritten, not re-rendered, so it stays sharp at any zoom. Blurriness comes from image downsampling, which is why a scanned signature can soften while a typed form stays crisp.

Can I compress to an exact size like 100 KB?

Yes, up to a point. The tool lowers quality until the file fits, but every document has a floor set by its text and structure. If it cannot reach the target without destroying the page, it tells you the smallest it could reach instead of handing you an unreadable file.

Is a compressed PDF still valid for an official upload?

Usually yes, provided the page count and the visible content are unchanged, which they are. Check the portal rules: a few require a specific DPI or a maximum dimension rather than a maximum file size, and downsampling can violate the first even while satisfying the second.

Does compressing remove the password?

No. An encrypted PDF has to be unlocked first; compression then applies to the decrypted copy you choose to keep.