What does a document compressor do?
A document compressor shrinks a file's size by recompressing the parts that take up the most space, usually the images inside it. This tool first detects what kind of file you dropped in, then applies the right strategy: PDFs are re-rendered page-by-page as optimized images, while Word, PowerPoint, Excel and OpenDocument files have their embedded images recompressed and downscaled in place - the surrounding text, formatting and layout are untouched.
Automatic file-type detection
Drop in a mix of files and the tool sorts out the rest. PDFs, Word documents (.docx), PowerPoint decks (.pptx), Excel workbooks (.xlsx) and their OpenDocument equivalents (.odt, .odp, .ods) are all recognized by file signature, and each one is compressed with the method that suits it. Legacy binary formats - .doc, .ppt, .xls - aren't supported; save a copy in the modern format first and it'll work fine.
Presets vs. target file size
Use the Light, Balanced, and Strong presets for a quick, predictable result. Light keeps images close to their original quality for documents where detail matters. Balanced is a solid default that noticeably shrinks most files without visible quality loss. Strong downscales large images more aggressively and lowers quality further, which is useful for documents packed with camera-resolution photos. Pick Custom to set image quality, maximum image dimension, and PDF resolution independently.
Use target file size when you have a hard limit to hit - an email attachment cap, an upload limit, or a specific size budget. The tool samples the file's largest images at a few quality levels, estimates the final size, and picks settings that should land at or under your target before rebuilding the full file.
What compressing changes
For Word, PowerPoint, Excel and OpenDocument files, compression only touches embedded raster images (JPEG and PNG) - text stays fully selectable, searchable and editable, and formatting, tables and charts are left alone. Oversized photos pasted into a document at full camera resolution are a common source of bloat; downscaling them to a sensible maximum dimension is often where most of the savings come from. PDFs work differently: each page is re-rendered and re-encoded as a JPEG image, which means the compressed PDF is no longer text-selectable, in exchange for much larger size reductions on scanned or image-heavy PDFs.
How to compress a document
- Drop one or more PDF, Word, PowerPoint, Excel or OpenDocument files onto the drop zone, or click Browse files.
- Pick a preset, adjust Custom quality/dimension/DPI, or enable target file size.
- Click Compress and watch the before/after size and savings per file.
- Download a file individually or grab the whole batch as a ZIP.
Common uses
Email and upload limits
Presentations and reports with embedded photos often blow past attachment limits. Use target file size mode to land safely under the limit without guessing at a quality level.
Slide decks and reports with photos
PowerPoint decks and Word reports built from full-resolution camera photos can shrink dramatically once those images are downscaled to screen size, with no visible difference in the deck or document.
Batch cleanup
Drop a folder of mixed PDFs, Word docs and spreadsheets, apply one preset to all of them, and download the whole set as a ZIP in one click.
Frequently asked questions
Does compressing a document upload my file anywhere?
No. Every file is opened, recompressed and rebuilt entirely inside your browser. Nothing is sent to a server.
Which file types does the document compressor support?
PDF, Word (.docx), PowerPoint (.pptx), Excel (.xlsx), and OpenDocument files (.odt, .odp, .ods). Legacy binary formats like .doc, .ppt and .xls aren't supported - save them as their modern equivalent first.
Will my document still be editable after compressing?
For Word, PowerPoint, Excel and OpenDocument files, yes - only the embedded images are recompressed and downscaled, so all text stays fully editable and searchable. PDFs are the exception: each page is re-rendered as an image, so the compressed PDF is no longer text-selectable.
Why didn't my file get much smaller?
If a document has few or no images - mostly text and tables - there's little for the compressor to shrink. Compression works best on files with embedded photos or scanned pages.
Is there a limit to how many documents I can compress?
No limit. Files are processed one at a time so memory stays manageable even with large batches.