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Compressing your PDF...
A PDF that will not send is a genuinely frustrating problem. Compression reduces the file size while keeping the document readable and the pages exactly the same dimensions they always were. Upload your file, let the tool optimise it, and download a smaller version — free, instant, and with no watermark added.
Understanding the cause makes the result predictable. In almost every case the size comes from images. A scanned page is a photograph of paper, and at 300 dots per inch a single A4 sheet can occupy several megabytes before compression. Multiply that by forty pages and the file is enormous even though it contains nothing but text you could have typed in a minute.
The other contributors are smaller but add up. Embedded fonts carry every character in a typeface even when the document uses a handful. Metadata and revision history accumulate quietly each time a file is edited and re-saved. Duplicate objects appear when the same logo is inserted on every page as a separate copy rather than a shared reference.
Several optimisations run together. Embedded images are recompressed at a more efficient ratio, which is where the bulk of the saving comes from. Duplicate objects are detected and collapsed into a single shared reference. Unused resources left over from earlier edits are discarded. The internal cross-reference structure is rebuilt in a more compact form.
Crucially, text and vector graphics are never touched. They are stored as instructions rather than pixels, so they occupy very little space to begin with and remain perfectly sharp at any zoom level after compression.
Scanned documents compress the most dramatically, often shrinking by 70–90%, because photographic data has enormous redundancy. Image-heavy brochures and presentations typically drop by half or more. Text-only reports may only shrink by 5–15%, since there was never much to remove. Files already optimised by their originating software may barely change at all — that is not a failure, it means the work was already done.
Anyone hitting an email attachment limit — the single most common reason people compress. Job applicants whose portfolio PDF exceeds an upload cap on an application form. Students submitting to systems with strict size restrictions. Offices archiving scanned paper, where a 90% reduction across thousands of files transforms the storage requirement. Anyone publishing PDFs online, since smaller files load faster and improve the visitor's experience.
Upload your PDF by dragging it onto the box or clicking to browse. The tool analyses the contents and applies the appropriate optimisations automatically. Download the result and compare — if the saving is not enough for your purpose, see the suggestions below for reducing size further.
When the file is still too large, the answer is usually to remove content rather than compress harder. Remove Blank Pages strips the empty backs of double-sided scans, which in a duplex-scanned document can halve the page count immediately. Split PDF divides the document into parts that individually fit under your limit. Delete Pages removes sections the recipient does not need. Between them these usually solve what compression alone cannot.
Compression is not reversible — discarded image data cannot be recovered from the smaller file. Always keep the original as your master copy, especially for anything heading to professional print, and use the compressed version only for sharing and distribution.
Your file is processed in memory and discarded the instant your download completes. Nothing is saved to disk, nothing is logged, and no copy is retained. The tool works in any modern browser on Windows, macOS, Linux, Android, and iOS with nothing to install.