PDF Compressor — Reduce PDF File Size Free Online
Two compression engines — Smart Compress preserves text and clickable links, Maximum Compress squeezes image-heavy and scanned PDFs to the smallest possible size. Strip metadata, convert to grayscale, and fine-tune with a precision image quality slider.
Reduce PDF file size online instantly — no sign up, no Adobe, no software to install. Choose Smart Compress to keep text selectable and links intact, or Maximum Compress to squeeze scanned and image-heavy PDFs to the smallest possible size. Grayscale conversion, metadata stripping, and a precision image quality slider give you full control. All processing happens entirely in your browser.
🗜️ Advanced PDF Compressor
Smart Compress · Maximum Compress · Grayscale · Strip Metadata
How to Reduce PDF File Size Without Losing Quality — Free & Instant
- Click Choose PDF File or drag and drop your PDF directly onto the upload area. Files up to 50MB are supported. No sign up needed — just upload and go.
- Choose your Compression Engine — Smart Compress to keep text selectable and links clickable, or Maximum Compress for the absolute smallest file size possible.
- Select a Compression Level — Low for minimal reduction, Medium for the best quality/size balance, High for aggressive compression, or Maximum for the tiniest file. To compress PDF below 1MB, start with High or Maximum.
- Tick any extra options — strip metadata to remove author and creator info, remove annotations to delete comments, or convert to grayscale for significantly smaller files. Grayscale is especially useful when compressing scanned PDFs.
- Adjust the Image Quality slider to fine-tune how images inside your PDF are compressed. Slide to 40–50% to reduce PDF size to under 200KB for forms and portals.
- Thumbnail previews show every page of your PDF that will be compressed — a quick visual check before you proceed.
- Click Compress PDF Now and watch the real-time progress bar as every page is processed entirely in your browser — no uploads, no server queues.
- See your savings stats instantly — then click Download Compressed PDF to save your smaller file. Perfect for job applications, CV uploads, university portals, and email attachments.
🚀 Premium Features Built for Real Results
This is not a basic file shrinker. It is a full-featured PDF compression suite with two intelligent engines, four compression levels, and professional options you would normally only find in paid tools like Adobe Acrobat Pro or Smallpdf Premium — all completely free, no sign up required. Whether you need to make a PDF smaller without Adobe, use a bulk PDF compressor free online for multiple files, or compress a scanned PDF that is bloated with images — this tool does it all without ever touching your files on a server.
🧠 Smart Compress Engine
Strips metadata, removes hidden objects and annotations, optimises PDF structure — all while keeping text fully selectable and links clickable.
⚡ Maximum Compress Engine
Re-renders every page as an optimised image and rebuilds the PDF from scratch. The same technique used by iLovePDF and Smallpdf for maximum compression.
📊 4 Compression Levels
Low (72 DPI, ~40% smaller), Medium (150 DPI, ~60%), High (300 DPI, ~75%), and Maximum (72 DPI, ~90% smaller) — choose the right balance for your needs.
⚙️ Strip PDF Metadata
Remove author name, creator software, title, subject, and keywords embedded in the PDF — cleans up your document and reduces file size.
🗑️ Remove Annotations
Delete all comments, sticky notes, highlights, and markup annotations from your PDF in a single click before compressing.
🖤 Grayscale Conversion
Convert colour PDFs to grayscale during compression for significantly smaller file sizes — ideal for text-heavy documents and reports.
📐 Image Quality Slider
Fine-tune exactly how images inside your PDF are re-encoded. Lower quality = smaller file. Find the perfect balance with the precision slider.
📄 Page Range Selection
Only need to compress certain pages? Set a custom range like 1–5, 8 and only those pages will be processed, saving you time.
📊 Live Savings Stats
See original size, compressed size, bytes saved, and percentage reduction in real time the moment compression completes.
🔒 100% Private & Secure
All processing happens locally in your browser using PDF-lib and PDF.js. Your PDF is never uploaded to any server, stored, or seen by anyone.
About This PDF Compressor
A PDF compressor reduces the file size of a PDF document by stripping unnecessary data, optimising internal structure, and re-encoding images at a lower resolution or quality level. This is essential when uploading a CV to a job portal, submitting an assignment to a university system, emailing a document within a size limit, or uploading to a government form that imposes strict file caps.
Need to do more with your PDFs? You can merge multiple PDFs into one file using our PDF Merger, or split a large PDF into separate pages with our PDF Splitter.
🔒 Your privacy is guaranteed. Unlike Adobe Acrobat Online, Smallpdf, and iLovePDF, this PDF compressor never uploads your file to a remote server. All compression happens locally in your browser using PDF-lib and PDF.js — your documents remain completely private and are never stored or accessed by anyone else.
Who Should Use This PDF Compressor?
Smart Compress vs Maximum Compress — When to Use Each
The two compression engines produce fundamentally different results. Choosing the right one is more important than any other setting.
🧠 Smart Compress
Optimises the internal PDF structure, strips hidden objects and metadata, and removes redundant data — without re-rendering any page content.
- Text stays fully selectable and copyable
- Hyperlinks and bookmarks remain clickable
- Fonts are preserved exactly
- Best for CVs, contracts, reports, presentations
- Typical reduction: 30–60%
⚡ Maximum Compress
Re-renders every PDF page as an optimised image and rebuilds the entire PDF from scratch at the chosen DPI and quality level.
- Text becomes non-selectable (image-based)
- Achieves far greater size reduction
- Best for scanned documents and image-heavy PDFs
- Use grayscale option for even smaller output
- Typical reduction: 60–90%
Low, Medium, High or Maximum — Which Level to Choose?
Each level sets a different image DPI target. The right choice depends on how small you need the file and what quality loss is acceptable.
Light reduction. Use when quality is the priority and the file is only slightly over the limit. Good for print-ready PDFs.
Best balance. Recommended default for CVs, assignments, and most general documents. Output looks identical at screen size.
Aggressive compression. Use to get under 1MB for job portals, government forms, and NHS submissions. Some image softness visible.
Smallest possible file. Use to reach 200KB or lower for visa applications and strict upload portals. Combine with grayscale for best results.
How This PDF Compressor Compares to Adobe, Smallpdf & iLovePDF
Paid tools like Adobe Acrobat Pro charge £17–£20 per month for PDF compression. Free online tools like Smallpdf and iLovePDF upload your files to their servers. This tool does neither.
| Feature | ✅ This Tool | Adobe / Smallpdf / iLovePDF |
|---|---|---|
| No file upload to server | ✅ Yes | ❌ Files uploaded |
| Completely free | ✅ Yes | Free tier limited or paid |
| Smart Compress (text-preserving) | ✅ Yes | Adobe only (paid) |
| Grayscale conversion | ✅ Yes | Rarely included free |
| Strip metadata | ✅ Yes | Sometimes |
| Remove annotations | ✅ Yes | Adobe only |
| Image quality slider | ✅ Yes | Limited on free tier |
| No watermark added | ✅ Yes | Watermark on free tier |
Common PDF Compression Problems & Fixes
📊 PDF is barely smaller after compression
Your PDF likely contains mostly vector graphics or already-compressed images. Switch to Maximum Compress engine and set level to High or Maximum. Also enable grayscale if colour is not needed — this alone can cut 20–30% from colour PDFs.
🔎 Text is no longer selectable after compression
You used Maximum Compress mode, which re-renders pages as images. Switch to Smart Compress instead — it preserves all text selectability, searchability, and clickable links while still reducing file size by 30–60%.
🚫 Still over the portal’s file size limit
Combine Maximum Compress engine + Maximum level + image quality at 35–45% + grayscale enabled. This is the most aggressive combination and brings most PDFs well under 1MB. For very strict limits (200KB), try reducing page count first using our PDF Splitter.
📷 Images look blurry in the compressed PDF
Raise the Image Quality slider to 75–85% and switch from Maximum to High compression level. If you used Maximum Compress engine, switching to Smart Compress will eliminate the blurriness entirely since it does not re-render page content at all.
Frequently Asked Questions
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Use Smart Compress mode with Medium compression level and set image quality to 80% or above. This strips metadata and removes unnecessary objects while keeping all text sharp, links working, and images looking clean. For most documents, file size drops by 40–60% with no visible quality difference whatsoever.
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Most job portals (Indeed, LinkedIn, Workday, NHS Jobs) require CVs and cover letters under 2MB or 5MB. Upload your PDF here, select Smart Compress at Medium level, and your file will typically drop well under those limits while keeping all text fully selectable and readable. No sign up required — just upload, compress, and download in seconds.
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University portals like Moodle, UCAS, and dissertation submission systems often cap uploads at 5MB or 10MB. Use Smart Compress at Medium or High level to bring your document under the limit. For dissertation PDFs with lots of images or charts, Maximum Compress at 60% image quality will produce the smallest possible file while keeping it readable.
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Select High or Maximum compression level and set the image quality slider to 50–65%. Enable grayscale conversion if your document does not need colour. For most PDFs, this will bring the file comfortably below 1MB. This is the setting to use for government forms, NHS portals, and visa applications that impose strict upload limits.
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Switch to Maximum Compress engine, set compression level to Maximum (72 DPI), drag the image quality slider down to 35–45%, and tick the grayscale option. This combination can compress a typical 5MB PDF down to under 200KB. Ideal for government portals, visa applications, and forms that specify a very small maximum file size.
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Yes — completely. This tool runs entirely in your browser, so there is nothing to download or install. Just open this page in Safari, Chrome, or Firefox on your Mac, upload your PDF, and compress it instantly. No Adobe Acrobat, no Preview tricks, no third-party apps needed.
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Adobe Acrobat Pro costs £17–£20/month just to compress PDFs — which is unnecessary. This free browser-based tool replicates the same compression results with zero cost. Upload your PDF, choose your compression level, and download a smaller file in seconds. No Adobe account, no subscription, no software.
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Scanned PDFs are essentially large image files, which is why they are so bulky. Use Maximum Compress mode with image quality set to 60–70% for significant size reduction. Enable grayscale conversion for even smaller files — ideal for black-and-white scanned documents. A 20MB scanned PDF can typically be brought down to 1–3MB using these settings.
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Currently this tool compresses one PDF at a time. To compress multiple PDFs, simply process them one after another — each takes only seconds. Bulk compression (processing multiple files simultaneously) is planned for a future update. For large batches right now, process each file sequentially using the same settings.
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Yes — this tool. There is no account, no email address, no registration of any kind required. Just open the page, upload your PDF, compress it, and download the result. No sign up, no login, no paywall. Free forever.
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No, never. All compression is performed locally in your browser using PDF-lib and PDF.js. Your PDF never leaves your device and is not sent to, stored on, or seen by any server anywhere. This is what makes this tool genuinely private — not just a promise.
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Absolutely not. This tool is completely free with no watermarks, no branding added to your PDF, no usage limits, and no hidden charges. Your compressed PDF is yours — clean and unmodified except for the compression.
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Yes. Open this page in Safari on iPhone or Chrome on Android, upload your PDF, choose your settings, and download the compressed file directly to your device. Everything runs inside your mobile browser — no app download, no storage permissions, no account needed.
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The portal may have a lower limit than you expected — some NHS, government, and visa portals cap at 200KB or even 100KB. Try Maximum Compress engine at Maximum level with image quality at 35–45% and grayscale enabled. If the file is still too large, split the PDF first using our PDF Splitter to reduce the page count before compressing.
Ready to Make Your PDF Smaller?
Free, instant, and 100% private. No watermarks, no signup, no software to install. Just a smaller PDF.
🗜️ Compress My PDF — It’s Free