MyAITools

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PDF Compressor

Shrink a PDF directly in your browser. Choose a level, see the before and after size, and download the smaller file. No upload, no watermark.

Drop your PDF here

or

PDF files up to 100 MB · works offline after loading

This tool runs entirely in your browser — your files are processed locally and are never uploaded to a server. You can even disconnect from the internet after the page loads.

How to compress a PDF

Five steps to a smaller PDF.

  1. Add your PDF

    Drop the file onto the zone or click “Browse files”. PDFs up to 100 MB are accepted.

  2. Pick a compression level

    Choose Low, Medium or High. The descriptions next to each option explain exactly what will change.

  3. Start compression

    Click “Compress PDF” and wait for the progress bar — large files are processed page by page.

  4. Compare the result

    The result panel shows the original and compressed sizes so you can judge whether the savings are worth it.

  5. Download the smaller file

    Click “Download PDF”. Use Reset to compress a different document.

What this tool does

PDF files grow large for two main reasons: heavy embedded images, and structural overhead left behind by the software that created them. This compressor attacks both, and is honest about which level does what.

Low rewrites the PDF’s internal structure losslessly with the pdf-lib library — pages, text and images stay bit-identical in appearance, and selectable text remains selectable. Savings here are real but usually modest.

Medium and High take a different route: each page is re-rendered as a high-quality image (150 DPI at Medium, 100 DPI with lower quality at High) and the document is rebuilt from those images. For scans and photo-heavy files this can cut the size dramatically — at the cost of turning text into pictures, so it is no longer selectable or searchable.

Key features

Three honest levels

Low, Medium and High each state plainly what they do and what you give up — no fake “90% smaller” promises.

Before and after sizes

The result panel shows both file sizes, so you always know the real saving instead of a guessed percentage.

No upload, no watermark

Compression runs in your browser with self-hosted libraries. The document never leaves your device and nothing is stamped onto it.

Lossless option

The Low level keeps every page exactly as it was, including selectable text — the right choice for contracts and official documents.

Scan-friendly

Medium and High are designed for the files that actually bloat: scanned paperwork and photo-heavy reports.

Works everywhere

Desktop, tablet or phone — with dark mode, keyboard support and readable contrast throughout.

Supported formats and options

Input: one PDF file up to 100 MB.

Output: a compressed PDF with the same page count and dimensions.

  • Low — lossless structural rewrite; text stays selectable.
  • Medium — pages re-rendered as 150 DPI images; best for scans.
  • High — pages re-rendered at 100 DPI with lower image quality; maximum reduction.

Practical use cases

  • Email attachment limits — get a scanned contract under a 20 or 25 MB mail limit without splitting it.
  • Upload portals — many application and government forms cap PDF size; Medium usually brings scans comfortably under.
  • Archiving paperwork — shrink folders of scanned invoices and statements before long-term storage.
  • Faster sharing — a smaller PDF opens and downloads faster for everyone you send it to.
  • Cleaning up exports — the Low level strips leftover editing overhead from documents exported by heavy desktop tools.

Limitations and notes

  • How much a PDF shrinks depends entirely on its contents. A well-optimised, text-only PDF may barely change at any level — no compressor can invent savings that are not there.
  • Medium and High convert pages to images: text becomes non-selectable, and zooming far in will eventually show pixels.
  • Very large PDFs must be held in memory while being rebuilt; desktop browsers handle big files best.
  • Password-protected PDFs cannot be opened — remove the password first, then compress.

Frequently asked questions

Why didn't my PDF get much smaller?

If a PDF is mostly well-compressed text and vector graphics, there is little left to save. The Low level is lossless, so savings come only from removing structural overhead. Medium and High re-render pages as images, which helps most with scans and photo-heavy files.

Will I lose my selectable text?

Only with Medium and High, which convert pages into images. Low keeps the original pages untouched, so text stays selectable and searchable.

Is my document uploaded?

No. Everything happens in your browser tab with self-hosted libraries. The file never leaves your device.

Is there a size limit?

Files up to 100 MB are accepted. Very large PDFs are processed page by page, but your device must hold the result in memory, so desktop browsers handle big files best.

Which level should I choose?

Start with Low if the document must keep selectable text (contracts, official filings). Choose Medium for scanned or photo-heavy files where you just need a readable, smaller copy. Use High only when size matters more than fine detail.

Will compression reduce the visual quality?

At Low, no — pages are untouched. At Medium and High the pages are re-rendered as images, so very fine detail can soften slightly; at normal reading zoom the difference is usually hard to spot.

Does it work offline?

Yes. Once the page has loaded, the compression libraries are cached by your browser and the tool keeps working with no internet connection.

Why is my already-small PDF unchanged at Low?

If a PDF was exported recently by efficient software, there is little structural overhead left to remove. Low is lossless by design, so it will never sacrifice content for size — try Medium or High if the file is image-heavy.

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