Two modes — Lossless strips hidden data with zero quality loss, Lossy re-renders pages for maximum size reduction. All processing in your browser.
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Drop your PDF here
or click to browse — any PDF up to 100MB
⚙️ Choose Compression Mode
No quality loss
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Lossless
Strips metadata, duplicate objects, unused resources and compresses internal streams. Text and images stay pixel-perfect.
✅ Full quality⚡ Fast~5–40% smaller
Max compression
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Lossy
Re-renders every page as a compressed image. Dramatically reduces file size but visually degrades text sharpness at low settings.
⚠ Quality reduced~50–85% smaller
🔵 What to strip (all checked = maximum lossless savings)
🟢Light~30–50% smaller
🟡Medium~50–70% smaller
🔴Aggressive~70–85% smaller
75%
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Compressing…
Loading…
✅ Done
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Original
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Compressed
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Saved
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Reduction
⚠️ The compressed file is the same size or larger. This PDF may already be well-optimised, or it has very little strippable data. Try Lossy mode for bigger reductions.
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What is a PDF Compressor?
A PDF compressor is a tool that reduces the file size of a PDF document so it is easier to share via email, upload to websites, or store on your device. Large PDFs are a common problem — a single scanned document or design file can easily be 10–50 MB, making it slow to send and frustrating to open on mobile.
Our free online PDF compressor works entirely in your browser. Your file is never uploaded to any server — compression happens locally on your device using PDF.js and pdf-lib, so your documents stay 100% private.
Lossless vs Lossy Compression — Which Should You Use?
Lossless compression is the safest option. It strips hidden data like metadata, embedded thumbnails, unused resources and compresses internal object streams — all without changing a single pixel of your content. Text stays sharp, images stay crisp. This is the right choice for business documents, contracts, reports and anything where quality matters.
Lossy compression re-renders every page as a JPEG image at reduced quality. This can shrink a PDF by 70–85%, which is great for sharing informally — but text may appear slightly less sharp at very low quality settings. Use it when file size matters more than print quality.
🔒 100% Private
Your PDF never leaves your device. No server upload, no storage, no tracking.
⚡ Instant Processing
No waiting for uploads or server queues. Compression starts immediately.
🔵 Lossless Mode
Strip hidden data with zero quality loss. Perfect for professional documents.
🔴 Lossy Mode
Re-render pages at reduced DPI for maximum size reduction — up to 85% smaller.
How to Compress a PDF — Step by Step
1
Upload your PDF
Click "Choose PDF" or drag and drop your file onto the upload area. Any PDF up to 100MB is supported.
2
Choose your mode
Select Lossless to preserve full quality, or Lossy for maximum compression. Lossless is recommended for most documents.
3
Adjust settings (optional)
In Lossless mode, pick what to strip — metadata, thumbnails, annotations. In Lossy mode, set image quality and DPI.
4
Compress and download
Click the Compress button. In seconds you'll see the original vs compressed size. Click Download to save your smaller PDF.
💡 Tip: If Lossless mode gives a small saving, your PDF is already fairly optimised. Try Lossy mode with "Light" quality for a bigger reduction without noticeable quality loss.
Frequently Asked Questions
Will compressing my PDF reduce its quality?
Only if you use Lossy mode. Lossless compression strips invisible hidden data — metadata, embedded thumbnails, redundant objects — so text and images remain pixel-perfect identical to the original. Lossy mode re-renders pages as JPEG images, which can slightly reduce sharpness, especially at very low quality settings. For most sharing purposes, even Lossy at 75% quality looks perfectly fine on screen.
Is my PDF safe? Does it get uploaded anywhere?
Your PDF stays entirely on your device. This tool uses JavaScript libraries (PDF.js and pdf-lib) that run locally in your browser — no data is ever sent to a server. This is especially important for sensitive documents like contracts, financial records or personal files.
Why is my compressed PDF larger than the original?
This can happen with PDFs that are already optimised, or with very simple text-only PDFs. In Lossless mode, there may be minimal hidden data to strip. In Lossy mode, PDFs with mostly text can sometimes grow slightly because the text is re-rendered as a JPEG image (which is less efficient than vector text). Try adjusting DPI or quality settings, or switch between modes.
What is the maximum PDF size I can compress?
The tool supports PDFs up to 100MB. Very large PDFs with many pages may take longer to process in Lossy mode since each page needs to be rendered. For extremely large files (50MB+), Lossless mode is faster as it doesn't need to render pages.
How much can I reduce a PDF file size?
It depends on the PDF content. Lossless mode typically saves 5–40%. Lossy mode can save 50–85%. PDFs with lots of embedded images compress the most — sometimes reducing from 10MB to under 1MB. Purely text-based PDFs compress less because text is already stored efficiently as vector data.
Can I compress a password-protected PDF?
The tool can process many encrypted PDFs using the "ignore encryption" option in pdf-lib, but heavily password-protected files may fail. If you get an error, try removing the password from the PDF first using a PDF reader, then compress it.
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