Select one PDF file to compress — stays on your device
Whether you're emailing a report, uploading a portfolio, or optimising assets for the web, I7 Pixel's PDF compressor gives you powerful size reduction in seconds — entirely in your browser, with no account and no file upload.
Compressing a PDF takes just four steps — no software to install, no account to create.
Understanding what gets compressed helps you pick the right settings for your documents and get the best results.
The majority of large PDFs owe their bulk to embedded raster images (photos, scanned pages, screenshots). This tool rasterises each PDF page with PDF.js at your chosen DPI, then re-encodes the result as a JPEG at your quality setting before embedding it into a brand-new PDF document. A scanned document with 300-dpi TIFF images might compress by 80%+ when re-encoded at 96 dpi / 72% JPEG quality — while readable text in the PDF remains vector-sharp because it is re-drawn, not photographed.
Beyond images, PDFs accumulate metadata (title, author, keywords, software version strings) and optional objects like annotations (comments, highlights, link rectangles) and form fields. Stripping these via pdf-lib's PDFDocument API removes kilobytes of overhead. The tool also saves the output with object streams enabled (useObjectStreams: true), which packs indirect PDF objects into compressed streams — a free efficiency gain that most PDF viewers fully support.
If your PDF contains only vector text and no embedded images — such as a word-processor export or code document — re-compression yields little gain because there are no image bytes to shrink. In these cases, only metadata stripping and object stream packing apply. The tool always reports the exact byte counts so you can see precisely what was saved, and flags the case with a hint suggesting lower DPI or quality if you want to try a raster-based approach.
Quick reference for choosing the right preset based on your use case and quality requirements.
| Preset | JPEG Quality | DPI | Typical Size Reduction | Best Used For |
|---|---|---|---|---|
| Low | 90% | 300 dpi | 10–30% | High-fidelity print-ready output where image quality must be preserved |
| Medium Default | 72% | 96 dpi | 40–70% | General-purpose sharing, email attachments, web upload — balanced quality |
| High | 50% | 72 dpi | 60–80% | Documents shared over chat or messaging apps where small size matters most |
| Max | 30% | 72 dpi | 75–90% | Archive thumbnails, previews, or cases where file size is the only priority |
| Custom | 20%–95% | 72–300 dpi | Varies | Fine-tuned control for specific file-size targets or quality requirements |
PDF compression is a frequent task across business, creative, and technical workflows wherever file size matters.
Answers to the most common questions about the PDF compressor.
Yes — completely free. No file limits, no account required, no watermarks, and no charges. Compress as many PDFs as you need.
No — never. All compression runs in your browser using PDF-lib and PDF.js. Your file is never transmitted, logged, or stored on any server.
Results depend on content. Image-heavy PDFs (scans, photo books) often shrink 70–90%. Text-only PDFs may see smaller gains since there are no images to recompress. The tool always shows you the exact bytes saved.
Low = 90% quality / 300 dpi (near-original). Medium = 72% / 96 dpi (balanced). High = 50% / 72 dpi (good for email). Max = 30% / 72 dpi (smallest file, lower image quality).
When using image re-compression, each page is rasterised as a JPEG — so text is rendered at your chosen DPI and encoded as an image. For crisp text, use Low preset at 300 dpi. If text sharpness is critical, try disabling "Re-compress images" and only stripping metadata instead.
The tool attempts to load encrypted PDFs with the ignoreEncryption option in pdf-lib. Fully locked PDFs requiring a password to open cannot be processed — remove the password with another tool first before compressing.
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All tools at I7 Pixel run in your browser — no uploads, no accounts, always free.