Flagship · Optimize PDF
Compress PDF without the guesswork.
Drop in your PDFs, pick Balanced (or a target size like 5 MB), and get a real before/after report. Private on-device processing — no signup, no uploads.
Drop PDFs here or
PDF only · up to 50 MB each on Free · up to 3 files · stays on your device
Your files are private and automatically removed after processing — compression runs in your browser, nothing is uploaded.
Files
No files yet — add a PDF above to see smart analysis and real savings.
Private by default. This tool runs in your browser — your files never leave your device and are automatically gone when you close the tab.
How it works
Step 1
Add one or more PDFs — validation, duplicates, and cancellation are built in.
Step 2
Choose Maximum, Balanced, High Quality, Custom, or a target size. Smart check recommends a starting point.
Step 3
Download each file or a ZIP, read the report, try stronger or restore previous.
Why it works well
Target-size mode
“Get my PDF under 5 MB” — the engine walks a quality ladder and reports honestly when a target is unreachable.
Smart analysis
Text-heavy, scanned, image-heavy, mixed, or already optimized — with a recommended preset and no invented estimates.
Batch + report
Independent per-file status, saved percentages, ZIP download, recompress, and restore.
Frequently asked questions
What is a PDF compressor?
A PDF compressor is a tool that reduces the file size of a PDF document, making it easier to upload, download, email, and share. PDF Compressor uses compression settings designed to reduce file size while balancing document quality. The amount of reduction depends on the PDF's contents, existing compression, images, and other embedded resources.
Do I need an account to compress a PDF?
No. Open the compressor, select or drag and drop your PDF, choose a compression mode, and process the file. No login, signup, or registration is required.
How do I resize a PDF file size?
To reduce a PDF's file size, open PDF Compressor, select your PDF or drag it into the upload area, choose a compression mode, and start compression. After processing finishes, compare the original and compressed file sizes and download the result if it meets your needs. The final file size depends on the document's contents and the compression settings used.
How to compress PDF to minimum size?
Choose Maximum Compression when your main priority is obtaining a smaller PDF file. This mode may reduce image quality or visual detail. If readability and appearance are more important, try Balanced or High Quality. Smart Auto can select a suitable strategy based on the PDF analysis implemented in the compression engine. Results vary depending on the original document.
Is the PDF compressor free to use?
Yes. PDF Compressor provides free PDF compression with no paid subscription required. Upload or select a PDF, compress it, and download the result.
Will compressing a PDF reduce its quality?
PDF compression can affect quality, depending on the document and compression settings. Maximum Compression prioritizes reducing file size and may reduce image detail. Balanced aims to balance file size and readability, while High Quality prioritizes visual clarity and may produce a larger file. Smart Auto selects an appropriate strategy using the capabilities implemented in the compressor. The actual results depend on the original PDF and the compression engine.
What is the difference between Maximum, Balanced, High Quality, and Smart Auto compression?
Maximum Compression prioritizes reducing file size and may result in lower image quality. Balanced aims to balance file-size reduction with readable text and acceptable visual quality. High Quality prioritizes visual clarity and may result in a smaller reduction in file size. Smart Auto analyzes the PDF using the functionality implemented in the compression engine and selects an appropriate compression strategy automatically. The results depend on the PDF’s contents and the compression settings supported by the engine.
Can I compress multiple PDF files at once?
Yes. Select up to 3 PDF files (up to 50 MB each), choose a compression mode, and process them. Each file has its own processing status, compression report, and downloadable result.
Are my files uploaded anywhere?
No. Compression runs entirely in your browser on your device — nothing is uploaded, nothing is stored on a server, and closing the tab removes everything from memory.
Is there a file size limit? What if my PDF barely shrinks?
The browser compressor handles up to 50 MB per file and 3 files per batch. For larger files, split the PDF first or process in smaller groups. Text-heavy or already-optimized PDFs have little to remove and save less — the report shows the real before/after result, never an invented estimate.