Does compression damage the document?

Maximum mode re-encodes images and can soften them. Text remains readable but inspect the result. Keep the original file so you can re-run with a gentler setting.

What is the difference between Standard and Maximum?

Standard preserves quality with a modest size reduction. Maximum reduces size aggressively but can visibly degrade photos and small text. Choose by destination.

Can I compress a scanned PDF?

Yes — scans are images, so they compress well. If you also want searchable text, run OCR before or after compression depending on whether you prioritise quality or size.

Will text stay searchable after compression?

Yes. Compression re-encodes images; the text layer is preserved, so selectable and searchable text survives.

Is it free and private?

Yes — free, unlimited, and processed in your browser with no uploads.

My email portal rejects my PDF — can compression fix it?

Very often yes. If the file sits just above the attachment limit, Maximum mode usually brings it under. Keep the higher-quality original for print and send the compressed copy where size is the constraint.

Should I prepare the document before compressing?

It helps. Deleting blank or duplicate pages and removing unused fonts makes compression more effective than any setting alone. For photo-heavy files, downscaling the source images first gives the biggest reduction.

What if the file is still too large after compressing?

Split it. Extract the image-heavy pages, compress those separately, and keep the text pages light. Targeting the few heavy pages usually halves the size without touching the readable core.

Can I compress several files at once?

Yes — the batch compression option processes multiple PDFs with the same settings and returns each one smaller. It is the practical choice for a folder of documents heading to the same destination.

Will compressed PDFs still open in every reader?

Yes — compression produces standard PDFs that open in any reader or viewer. The settings affect image quality and file size, not compatibility with PDF software.

How much smaller can I expect a photo-heavy PDF to get?

Photo and scan-heavy files often shrink to a fraction of their original size, because images dominate the weight and re-encoding removes redundant detail. Text-only files shrink far less — there is simply less to remove.

What should I do if a compressed file looks bad?

Re-run with a gentler mode or keep the original and compress less aggressively. If only a few image-heavy pages are the problem, extract them, compress them separately, and merge them back.

How to reduce PDF file size without losing quality: a practical checklist

Guide · Updated 2026-08-13 · Optimize cluster

Reducing a PDF file size is mostly about its images: photos and scans dominate file weight, while text compresses well. Before compressing, know what is inside the file. After compressing, open the result and check that text is still readable and important images are not visibly degraded. No tool can promise a fixed size reduction — the outcome depends on the content.

Every PDF size question comes back to one rule: text is small, images are big. A 50-page text-only report might weigh under a megabyte; a 10-page document of photos can exceed fifty. Understanding this makes compression predictable instead of mysterious.

This guide is a practical checklist — what to inspect before you compress, and how to confirm the result is acceptable after.

Why PDFs get large

High-resolution photos and scans stored at full camera or scanner resolution.
Many images repeated across pages (logos and headers on every page).
Embedded fonts, especially several weights of the same family.
Vector illustrations with excessive detail.
Uncompressed or lightly compressed image data.

What compression does

Compression re-encodes the file: images are resampled and re-encoded at a chosen quality, and other structures are compacted. Standard mode is gentle — it keeps images sharp and mostly preserves quality. Maximum mode is aggressive — it shrinks files hard but can soften photos and make small text slightly less crisp.

Choose the mode by destination. Maximum mode is right for email attachments and quick shares. Standard mode is safer for documents that will be printed, archived or read closely.

Before you compress

Identify the biggest contributor: images, scans or fonts.
If a document is mostly photos, expect strong size reduction.
If a document is mostly text, expect modest reduction — text is already small.
Keep the original file — compression is lossy in maximum mode.

After you compress

Open the result and read the smallest text at normal zoom.
Zoom into an image-heavy page and look for artefacts.
Compare file sizes and confirm the reduction is real.
Check that page count and content are unchanged.
If text is blurry, re-run with a gentler setting.

Realistic expectations

Content	Typical result	Why
Text-only document	Small reduction	Text is already compact
Photo-heavy document	Large reduction	Images dominate the weight
Scanned document	Large reduction	Scans carry redundant detail
Mixed document	Moderate reduction	Depends on the mix

Compression in a workflow

Compression pairs naturally with sharing: compress before emailing, uploading or publishing. For a document that will be printed, compress conservatively or skip it. If a file must stay searchable, compressing a text-layer PDF keeps the text selectable — only the images are re-encoded.

Preparing a document before compressing

A little preparation goes further than any compression setting. Remove pages you do not need, delete duplicate images, and strip unused fonts if your PDF tool offers that. Compression then works on a leaner file, and the result is smaller than compressing the bloated original would be. For a presentation deck full of large photos, exporting a lighter version of the images before building the PDF is often the single biggest win.

Delete blank or duplicate pages before compressing.
Remove embedded fonts you do not use.
For image-heavy PDFs, downscale the source images first.
Split a huge document and compress the image-heavy part harder.

Compressing for email and upload limits

Email attachments and upload portals often cap file size — 10 MB and 25 MB are common limits. If your PDF sits just above the limit, Maximum mode usually brings it under without much visible damage for on-screen reading. Keep a copy of the higher-quality version for print, and send the compressed one where size matters more than perfect fidelity.

When a file still exceeds the limit after compression, the next step is not more compression — it is splitting. Extract the pages that must travel as a PDF, compress those, and send the rest separately or as images. A 40 MB deck is often a few heavy image pages plus fifty light text pages; targeting the heavy pages alone can cut the file in half without touching the readable core.

For documents that will only ever be read on a screen — which is most attachments — moderate compression is effectively invisible. The files that suffer visibly are print-oriented ones with fine text or photographs that will be viewed closely.

Privacy

Compression runs locally in your browser. The PDF is re-encoded on your device and the smaller file is generated without any upload. Nothing about your document is transmitted.

Frequently asked questions

The file is probably text-heavy or already optimised. Text compresses well the first time but leaves little to remove. Image-heavy files are where the big reductions happen.