PDF Compressor Online — Free, No Upload, No Account
Reduce PDF file size for email, uploads and sharing — three compression levels, batch processing, full privacy.
Compress PDF FreePDF files — three compression levels, no upload, no account, no limits.
The free online PDF compressor that works in your browser. Reduce PDF file size for email, upload, sharing and web use. Three compression levels — low, medium and high — let you balance size reduction and document quality. No upload, no account, no limits.
Free online PDF compressor — reduce PDF file size for any use case
Large PDF files can slow down uploads, email sending and website performance. Compressing PDFs helps reduce file size while keeping text readable and images clear. This free online PDF compressor runs entirely in your browser — no upload, no account, no server access. Your documents stay on your device throughout the entire process.
PDF files can often be reduced by 50–90% depending on content and compression level. A 20 MB presentation exported to PDF can compress to 2–4 MB. A 50-page scanned contract at 45 MB can become 5–8 MB on medium compression. The compression targets the main sources of PDF file size: embedded images (the largest contributor), uncompressed data streams, and redundant objects accumulated through editing.
Three compression levels give you full control. Low compression removes metadata and redundant objects without touching image quality — ideal for archival documents and print-bound files. Medium compression downsamples embedded images to 150 DPI — the best setting for email attachments, client deliveries and shared documents. High compression pushes image resolution down to 96 DPI for maximum size reduction — for files that must fit strict limits or load fast on slow connections.
Understanding what is inside your PDF helps you choose the right level. Text PDFs — created from Word, Google Docs, Excel or InDesign — compress very efficiently because only the embedded images need to be reduced. Scanned PDFs — photographs of printed pages stored inside a PDF — are inherently large and respond well to medium compression, though high compression can make text hard to read at small font sizes. Knowing which type you have helps you pick the right level and set accurate expectations for the output.
Compress PDF for email to fit Gmail and Outlook attachment limits. Reduce PDF size for upload to document portals, HR systems and government forms. Optimize PDF for web — faster downloads and lower server bandwidth. Make PDF smaller for sharing via links on Google Drive, Dropbox or Notion. All of these workflows run in one tool, free, with no account and no upload.
Also try PDF Merge to combine files, compress PDF online for a quick workflow, or convert PDF to JPG to extract pages as images.
- 1Upload your PDF files
Drag and drop one or more PDF files onto the upload area, or click to browse. No file size limit — all processing runs locally in your browser. Nothing is uploaded to any server. Upload any number of PDFs in a single session.
- 2Choose the compression level
Select low (minimal quality change), medium (best balance for email and sharing) or high (maximum size reduction). For most business documents and email attachments, medium delivers 40–70% size reduction with no visible quality change at screen resolution.
- 3Compress all files
Click "Compress All". Files are processed in your browser — no upload, fully private. Compression progress is shown per file. All files are processed without leaving your device.
- 4Download and verify
Each file shows original size, compressed size and savings percentage. Download individually or click "Download All" for a ZIP archive. Open the compressed PDF and verify that text is readable and any critical charts or images are clear before sending or uploading.
Who uses this online PDF compressor
Compress PDF for email — business documents and contracts
PDF is the standard format for contracts, reports, invoices and proposals — all sent by email. Gmail limits attachments to 25 MB; Outlook to 20 MB. Many corporate email systems enforce 10 MB limits. Compress PDF for email attachment with medium compression — a 15 MB report becomes 3–5 MB, well under any limit. Smaller PDFs also open faster in mobile email clients and are less likely to be blocked by recipient spam filters due to attachment size.
Reduce PDF size for upload — portals and platforms
Document upload portals — government forms, legal platforms, HR systems, insurance portals — routinely enforce 5–10 MB file size limits. Reduce PDF file size for upload to ensure documents are accepted without rejection errors. Medium compression is the standard choice: significant size reduction with no change to text quality, signatures or form content.
Optimize PDF for web — faster downloads and lower bandwidth
PDFs served as download links on websites add to page weight and server costs. A press kit, a product catalog or a white paper at 30 MB creates 30 MB of server transfer for every download. Compress PDF for web use — compress to medium or high level to reduce download time. Smaller files load faster on mobile connections, are less likely to time out and cost less to serve.
Compress scanned PDF — reduce file size of scanned documents
Scanned PDFs are the largest type: each page is a full raster image, often 300 DPI from a scanner, producing files of 1–5 MB per page. A 20-page scanned contract can be 40–80 MB. Medium compression reduces scanned PDFs significantly — downsampling page images from 300 DPI to 150 DPI with quality reduction cuts file size by 60–80% while keeping text legible at 100% zoom. For documents that will only be read digitally, this is the right tradeoff.
Why this is the best free PDF compressor online
Three compression levels, privacy-first processing, and batch capability — built for document workflows.
Reduce PDF size while keeping text readable and images clear
The compressor applies image downsampling, stream compression and redundant object removal to shrink PDF file size. Three compression levels — low, medium and high — let you control the tradeoff between file size and document quality. Low preserves all visible detail; medium balances size and readability; high achieves maximum size reduction for documents where file size matters most. Text content remains fully selectable and searchable at all compression levels.
Your PDF files never leave your device
All compression runs locally in your browser using JavaScript and pdf-lib. No PDF file is uploaded to any server, transmitted over the network or stored anywhere. The tool works without an internet connection after the initial page load. This makes it safe for compressing confidential documents, legal files, financial statements, medical records and any content that cannot touch a third-party server.
Compress multiple PDF files in one session
Upload as many PDF files as you need — there is no batch size limit. All files are processed in your browser. Compression progress is shown per file. When all files are done, download them individually or use the "Download All" button to get a ZIP archive. Compress an entire document set or archive in a single session — no account, no upload queue, no waiting.
Complete guide to compressing PDF files
Text PDF vs scanned PDF — why it matters for compression
PDF files fall into two fundamentally different categories, and understanding the difference is critical for getting good compression results. A text PDF (also called a native PDF) is created digitally — exported from Word, Google Docs, InDesign, Excel or any other application. Its content is stored as text, vector graphics and embedded images. This type compresses very well: the text and vector content are already space-efficient, and the embedded images are where most of the file size comes from. Compressing their resolution and quality produces dramatic size reductions. A scanned PDF is a photograph of a printed page — every page is a raster image stored inside a PDF wrapper. Scanned PDFs tend to be very large (1–5 MB per page) because each page is a high-resolution image. Compression works differently here: it recompresses those page images to reduce their quality and resolution. Aggressive compression of scanned PDFs can make text hard to read, especially at small font sizes. For scanned PDFs, use the "low" or "medium" compression level to maintain legibility. For text PDFs, "medium" or "high" compression is safe and usually produces the best size reduction.
Why PDF files are large — and what you can do about it
Large PDF file size almost always comes from one of three sources. First: embedded images. A PDF report with 10 full-resolution photos at 3 MB each is a 30 MB PDF before any other content. Compressing the images inside the PDF — reducing their resolution and quality — is the single most effective way to reduce PDF size. Second: redundant content. PDFs accumulate unused objects, duplicate font data and unnecessary metadata as they pass through editing tools. Removing this redundant data can reduce file size without changing the visible content at all. Third: uncompressed streams. PDF data streams can be stored uncompressed — applying standard compression algorithms (like deflate) to these streams reduces file size without any quality change. A good PDF compressor addresses all three sources simultaneously. PDF files can often be reduced by 50–90% depending on content and compression level.
Choosing the right compression level for your use case
The right compression level depends entirely on how the document will be used. Low compression: removes redundant objects and applies stream compression without touching image quality. Produces modest size reductions (20–40%) with zero visible change. Best for: archival copies, documents with precise graphics, PDFs that will be printed professionally, or any file where quality must be preserved exactly. Medium compression: downsamples embedded images to 150 DPI and applies quality reduction. Produces larger size reductions (40–70%) with no noticeable change at screen resolution. Best for: business documents, client deliveries, documents shared by email where 150 DPI is sufficient. High compression: downsamples embedded images to 96 DPI and applies aggressive quality reduction. Produces maximum size reductions (50–90%). Best for: email attachments with strict size limits, documents that will only be read on screen at 100% zoom, PDFs where file size is more important than image fidelity. Text remains readable at all compression levels — only the embedded image quality and resolution are affected.
How to compress PDF for email — size limits and best practices
Email providers impose attachment size limits — typically 10 MB (Gmail, Outlook) to 25 MB. A multi-page PDF report, a scanned contract or a presentation exported to PDF can easily exceed these limits. Compressing a PDF for email has a clear target: get the file below the attachment limit while keeping the text readable and any important images clear enough for the recipient to understand the content. For most business documents, medium compression achieves this — a 15 MB PDF becomes 3–5 MB, well within any email limit, with no noticeable quality change at screen size. For documents with many high-resolution photos or graphics, high compression may be needed to reach the target size. For critical documents with precise graphics or charts, use low compression to preserve all visual detail and share via a file link (Google Drive, Dropbox) instead of an attachment if the compressed file is still too large.
Frequently asked questions about PDF compression
Yes — completely free. No account, no payment, no watermark, no daily limit. Compression runs in your browser on your device, so there are no server costs. Compress as many PDFs as you want, forever free.
Upload your PDF to this tool, choose a compression level (medium works for most use cases), click "Compress All" and download the compressed file. The process is free — no account, no watermark, no file size limit.
PDF files can often be reduced by 50–90% depending on content and compression level. Documents with many embedded images (presentations, reports with photos) compress the most. Text-only PDFs compress less but still see 20–40% reduction from redundant object removal.
Text content remains fully readable at all levels. On medium and high compression, embedded images are downsampled to lower resolution — visible only when zooming into photos inside the PDF. Low compression does not change image quality at all.
Upload your PDF, select medium compression, click "Compress All" and download. Medium compression reduces most business PDFs by 40–70% — enough to fit within Gmail and Outlook attachment limits.
The most common cause is embedded images — a report with 10 high-resolution photos at 3 MB each creates a 30+ MB PDF before any other content. Other causes: scanned pages (each page is a full raster image), uncompressed data streams, and redundant editing objects accumulated over multiple saves.
Low: minimal quality change, 20–40% reduction — for archival, print or precise graphics. Medium: best for email and sharing — 40–70% reduction with no visible quality change at screen size. High: maximum reduction, 50–90% — for strict size limits; text stays readable, images are lower quality.
Yes. All compression runs locally in your browser — your PDF files are never uploaded to any server, never stored, and never accessible to anyone else. Safe for confidential documents, contracts and sensitive content.
Yes. Upload any number of PDF files, choose the compression level and click "Compress All". Download individually or use "Download All" for a ZIP archive.
Yes. Open the tool in Safari (iPhone) or Chrome (Android), upload PDF files, choose compression level and download. No app required.
This tool processes files locally — no upload, no server, no daily limit, always free. Smallpdf and ilovepdf upload your files to their cloud and restrict free usage (daily limits, file size caps). For privacy and unlimited use, this tool is the better choice.
Yes. After the page loads, all compression runs locally on your device. No internet connection is required.
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