Compress PDF, images & Office files

slimdocs compresses PDFs, JPEG/PNG images and Word/Excel/PowerPoint documents by optimizing the heavy parts — embedded photos and scans — while leaving vector text and line art completely untouched. The result is a much smaller file that still looks perfect.

How to use it

1. Open the compressor and drop in your file.
2. Pick a level — Balanced is the recommended default; Light is visually lossless; Maximum and Extreme go smaller.
3. Compress, then compare the before/after sizes.
4. Download. Your file is processed in memory and never stored.

What actually makes a file large

Almost every oversized document is heavy for the same reason: images. A page of plain text is only a few kilobytes, but a single full-colour scan at 600 DPI can be several megabytes on its own. Photographs, screenshots, exported charts and embedded logos add up quickly, and most files also carry duplicated fonts, redundant copies of the same image, and leftover revision history that no longer serves any purpose.

Compression works by re-saving those heavy parts sensibly — downsampling images to a resolution that still looks sharp on screen and in print, re-encoding them with an efficient codec, and rewriting the file structure so nothing is stored twice. The page looks identical; the byte count drops sharply.

Text stays sharp — we never flatten your document

The most important thing slimdocs does is leave your text and vector graphics completely alone. Many low-quality compressors take a shortcut: they turn each page into a single flat image, which destroys selectable text, breaks screen-reader accessibility, and makes the file blurry when you zoom in. slimdocs never does this.

Real text remains real text, so the compressed file stays searchable, copy-pasteable and accessible. Only the embedded photos and scans are optimised, which is why a contract or report can shrink substantially without any visible loss in quality.

Choosing the right compression level

The best setting depends on where the file is going. Use this as a quick guide:

Light	Visually lossless. Strips redundant data and lightly optimises images — ideal when the file must look identical to the original, e.g. for printing.
Balanced	The recommended default. Large size reduction with no loss you would notice on screen. Right for email, uploads and everyday sharing.
Maximum	Aggressively downsamples images for the smallest practical file. Great for web previews and tight upload limits.
Extreme	Pushes images to the lowest sensible resolution. Use when a hard size cap leaves no other choice and fine image detail does not matter.

How much smaller will my file get?

It depends entirely on what is inside. Scanned and photo-heavy PDFs commonly shrink by 70–90%, because their images carry far more detail than any screen needs. A PDF that is already mostly text might only shrink a little — there simply is not much to optimise, and that is a sign your file was already efficient.

If a file barely shrinks, that usually means it was already well-compressed or contains little image data. Trying a higher level rarely helps in that case and may begin to soften photographs, so Balanced is almost always the right starting point.

Processed in memory, then deleted

Compressing a document well needs more computing power than a browser tab can provide, so slimdocs does the heavy work on a secure server. The crucial difference from typical online tools is what happens next: your file is held in memory only for the few seconds it takes to process, streamed straight back to you as a download, and then permanently erased. Nothing is written to long-term storage, indexed or shared, and the entire connection is encrypted.

That matters for the documents people actually compress — contracts, payslips, medical records, ID scans and tax forms. With slimdocs, none of them ever linger on a server after your download begins.