Optimize PDF

    Reduce PDF file size by removing metadata and optimizing structure

    How to compress a PDF

    Our PDF compressor shrinks file size by stripping out metadata, flattening form fields, and rewriting the document structure more efficiently. Everything runs in the browser — your PDF is never uploaded, logged, or stored on our servers. You get the compressed file back in seconds with a clear side-by-side of the original and new sizes.

    Step-by-step guide

    1. Upload the PDF. Drag or browse to your file. The original size appears immediately.
    2. Pick a compression level. Low strips metadata only (safe for sensitive documents). Medium adds structural improvements — the right choice for most PDFs. High also flattens forms and annotations for maximum savings but removes interactivity.
    3. Compress and download. Click the button. You'll see the exact percentage saved — sometimes 5%, sometimes 70%, depending on what's inside.

    Which compression level should you pick?

    • Low — contracts, certificates, or any document where you want to preserve form fields and annotations. Typical saving: 5–15%.
    • Medium — general use: reports, e-books, invoices, scanned documents. Typical saving: 15–40%.
    • High — when you just need to get under an email attachment limit and do not need form fields. Typical saving: 30–70% on form-heavy PDFs, less on image-heavy ones.

    When compression helps most

    • Getting a PDF under the 25 MB Gmail or 20 MB Outlook attachment limit.
    • Uploading documents to portals that cap file size (job applications, tax filings, universities).
    • Saving cloud storage on large document archives.
    • Speeding up email delivery and mobile downloads.
    • Preparing web-viewable PDFs that load quickly in browsers.

    Why sometimes the savings are small

    If a PDF is mostly high-resolution photographs or scans that are already JPEG-compressed inside the file, there is little extra fat to trim. In those cases, consider:

    Frequently asked questions

    Will compression blur my text or images?

    No. This tool does not re-encode images at lower quality — it only removes redundant structure and metadata. Text stays selectable, images keep their original resolution.

    What does "flatten forms" mean?

    At high compression, interactive form fields (checkboxes, text inputs, signatures) are rendered into the page as static content. The form can still be read but no longer accepts new input. Use Low or Medium to preserve fields.

    Can I compress the same PDF multiple times?

    Yes, but you usually hit a floor after the first pass. A second run rarely saves more than 1–2% since the easy wins are already gone.

    Is the compressed PDF still valid for e-signatures?

    Low and Medium compression preserves signature fields. High compression flattens them — after flattening, existing visible signatures remain as images, but the cryptographic signature is removed.

    Are my files ever uploaded to a server?

    No. Compression runs in your browser with the open-source pdf-lib library. The file never leaves your device.