Shrink a PDF that's too big to send
A 30 MB PDF that bounces off an email attachment limit, a portfolio that's slow to upload, a scanned contract that won't fit a web form's size cap. These are the moments you need a smaller file, and the usual worry is that "smaller" means "blurry text and muddy images." It doesn't have to. Most oversized PDFs are heavier than they need to be because of redundant internal structure, uncompressed object streams, and image data saved at far higher quality than anyone will ever notice.
The PDF compressor trims that waste right in your browser. Your file is read locally and never uploaded to a server, so there's no waiting on a queue, no sign-up, and nothing leaves your device. You pick how aggressive you want to be, preview the estimated savings before you commit, and download the result. Below is how to do it while keeping the document readable and sharp.
How to compress a PDF without losing quality
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Open the tool. Go to the PDF compress tool. It loads instantly and works entirely in the browser tab, so the file you choose stays on your computer.
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Add your PDF. On the Upload tab, drag your file onto the drop zone or click Select PDF File. The tool accepts files up to 100 MB. Once it loads, you'll see the original size and the page count, which gives you a baseline to compare against.
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Move to Settings and pick a compression level. Open the Settings tab and choose one of four levels:
- Low (Best Quality) — the lightest touch. Use this when quality matters most and you only need to shave off some weight.
- Medium (Balanced) — the safe default for almost every document. Good size reduction with no visible drop in text or image clarity.
- High (Smallest Size) — squeezes hardest. Best for image-heavy files where you're prioritizing a small attachment over pixel-perfect photos.
- Custom (Fine-tune) — gives you a slider, covered next.
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Use Custom for precise control (optional). Select Custom to reveal an Image Quality slider from 10% to 100%. Higher percentages keep images crisper; lower percentages make the file smaller. For documents that are mostly text, you can drop this fairly low and still keep the words perfectly legible. For photo-rich PDFs, stay around 70–85% to protect the images. This is the real lever for "smaller without looking worse."
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Set color mode and advanced options. Choose Full Color or Grayscale depending on the document. You can also enable Font subsetting optimization (strips unused font data) and Remove document metadata (drops author, title, and similar tags). Both shrink the file a little more without touching the visible content.
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Check the estimate. The settings panel shows your original size, an estimated compressed size, and the estimated savings. If the projected result isn't small enough, bump the level up or lower the image-quality slider, then read the estimate again before processing.
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Compress and download. Click Compress PDF. Processing happens locally, then the Result tab opens with the final size. Download the optimized file. Open it once to confirm the text is sharp and images look right before you send it.
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Compress several files at once (optional). If you have a batch, use the Batch tab to queue multiple PDFs with the same settings and process them together instead of one at a time.
Tips
- Start at Medium and only go higher if needed. Most files reach a comfortable size at Medium with no visible quality loss. Reserve High for when you're still over a hard limit.
- Text-only PDFs compress safely and aggressively. Documents without photos (reports, invoices, e-signed contracts) can take a low Custom quality setting because there are no images to degrade.
- The biggest savings come from images. If your PDF is built from scanned pages or full-bleed photos, the image-quality slider matters far more than the metadata options. For standalone images you plan to embed later, run them through the image compressor first.
- Keep the original. The download is a new file. Hold on to your source PDF in case you want to recompress with different settings.
- Wrong tool for the job? If your real goal is fewer pages rather than a smaller file, use the PDF splitter to keep only what you need, or the PDF merger to combine documents before compressing once.
Common problems
- "File size exceeds 100 MB limit." The tool caps uploads at 100 MB. Split the document with the PDF splitter and compress the parts separately, or remove heavy pages first.
- Barely any size reduction. This usually means the PDF is already well optimized, or it's image-heavy and you used a gentle level. Try High, or drop the Custom image-quality slider. For very large scanned PDFs, the in-browser tool optimizes structure; truly extreme image compression sometimes needs desktop software.
- Images look soft after compressing. You went too aggressive. Recompress from your saved original at Medium, or with a higher Custom quality value (try 80–90%).
FAQ
Will compressing make my text blurry? No. Text in a PDF is stored as fonts and vectors, not pixels, so it stays crisp regardless of the level you choose. Only embedded images are affected by the quality setting, which is why text-heavy files compress so well.
Is my file uploaded anywhere? No. The compression runs in your browser, so the PDF never leaves your device. There's no account, no upload, and nothing stored on a server.
What's the best setting to keep quality while still shrinking the file? Medium is the balanced default and is invisible for most documents. If you need more control, switch to Custom and keep the image-quality slider around 80–85% — small enough to save real space, high enough that images stay clean.
Can I compress more than one PDF at a time? Yes. The Batch tab lets you queue several files and process them with the same settings in one go.
Want to do more with your documents? Explore the rest of the lineup in the complete guide to PDF tools, or pair this with the PDF merger to combine and shrink in one workflow.