About reduce PDF file size
This page is organised around an outcome rather than a technique: you have a number you need to get under, and you want to judge what reaching it would cost. There is no predictable reduction curve or guaranteed target size. The engine attempts object-stream rewriting and, when enabled, limited metadata cleanup; it does not consolidate duplicate resources, remove every unused object or subset fonts. Cleanup targets eight standard Info keys and detaches the catalog XMP reference, but custom entries and detached XMP bytes may remain. The resolution preset changes the downsampling target between 220, 150 and 110 DPI, while the JPEG quality slider stays independent. Downsampling uses recoverable image placement, and supported images can still be re-encoded when below the target. Each image replacement must be smaller to be accepted. Lower settings can soften scanned text or introduce blocking and haloing, so change one control at a time and inspect the intended reading or print size rather than assuming a quality percentage predicts appearance. The complete rewritten candidate is returned only if smaller; otherwise the original bytes, images and metadata are returned unchanged. That result describes this attempt, not a document's smallest achievable size. Keep the original and accept a smaller version only when its appearance and your actual size limit are both acceptable.
How to reduce PDF file size
- 01
Load the document
Add one unencrypted PDF, up to 250 MB and 5,000 pages. The current file size is shown in the file list; browser memory can constrain practical processing below those limits.
- 02
Start with a higher resolution target
Try the 220 DPI preset first if detail matters. The quality slider is independent and remains at its selected value; inspect the returned file even if it clears your size target.
- 03
Step down as needed
Still too large? Try 150 or 110 DPI, or lower JPEG quality separately. Each attempt reports the returned size, including an unchanged original when no smaller candidate was produced.
- 04
Download the version you accept
Download once both size and appearance are acceptable. The -compressed.pdf suffix is used even when the original bytes are returned; read the report rather than relying on the name.
What this tool does
- Resolution presets change the DPI target while JPEG quality remains independently adjustable
- Re-runnable without reloading the file, so stepping down through settings is quick
- Reports the resulting size every time so you know when to stop
- Object-stream rewriting is attempted at every level; limited metadata cleanup runs only when enabled
- Local processing with no upload; one PDF at a time, up to 250 MB and 5,000 pages
Limitations worth knowing
Every PDF tool has constraints. Stating them plainly is more useful than discovering them halfway through your work.
- No setting or number of attempts guarantees a target size. A no-saving result does not prove that another compression method could not help.
- Text-heavy files may mainly benefit from structural rewriting and limited metadata cleanup. Embedded fonts are not subset, and unsupported images may remain unchanged.
- Accepted downsampling and JPEG re-encoding are lossy at every preset. Keep the original; higher settings do not make changed image data reversible.
- Already-compressed images may not yield smaller replacements. If the whole candidate is not smaller, the original PDF is returned with its images and metadata unchanged.
How your file is handled
This tool runs entirely inside this browser tab. When you choose a file, your browser reads it from your own disk and hands the bytes to JavaScript running on this page — no network request carries your document anywhere. You can confirm that yourself: open your browser’s developer tools, switch to the Network panel, and run the tool. You will see no upload.
Nothing is stored after the fact. Closing or reloading this tab discards the file, the result and everything derived from them, because none of it ever left your machine. Read how local processing works.
Questions about reduce PDF file size
Can I reduce a PDF to a specific size, like exactly 2 MB?
Not reliably. The result depends on image content, existing compression, browser decoding support and file structure. Try a setting, read the returned size and inspect the appearance before deciding whether to reduce further. There is no target-size control or guaranteed number of attempts. If the candidate is not smaller, the original is returned; consider splitting the document if the receiving system accepts separate parts.
Which single setting reduces size the most?
It depends on the file. Reducing the DPI target can help when supported images contain more pixels than needed for their measured placement and intended use. Lower JPEG quality can reduce encoded bytes without changing dimensions, but may introduce artefacts. Neither is always the stronger control, and fine detail can matter at zoom or in print. On this page the preset changes DPI only, so compare changes to it and the quality slider separately.
Will reducing the size make my text blurry?
The engine does not deliberately re-encode text drawing operators or embedded fonts as images. Text inside a scan, however, is part of an image and can soften or acquire JPEG artefacts when a replacement is accepted. This tool does not validate every rendering detail, so inspect small text and important pages in the returned file at the size you will use.
My PDF is already small and this barely helped. Why?
This attempt may have had little to save: the file could contain few supported images, already-compressed streams or image encodings the browser cannot decode. Structural rewriting and limited metadata cleanup may also yield little benefit. That does not prove the file is at its smallest possible size. The report distinguishes a smaller rewrite from the original returned unchanged.
Tools that pair with this one
- Compress PDFMake a PDF smaller by re-encoding its images and cleaning up its internals.
- PDF Size ReducerFor the PDF that a form, portal or mail server has just refused.
- Compress PDF for EmailTry reducing an attachment, then check its size against both mail providers' limits.
- PDF Size AnalyzerA byte-level breakdown of where your PDF weight actually is.
- Split PDFCut one PDF into several documents — by range, by interval or page by page.
- PDF OptimizerTry structural rewriting and image compression, then check the returned file and reported saving.
Read more about this
- How to reduce PDF file size to meet a limitWritten for the case where a number is imposed on you — an email cap or an upload form. How to converge on a target quickly and what to do when you cannot reach it.6 min guide
- How to compress a PDFCompression is four independent levers, three of them lossy. This guide explains what each one does to your pages so you can choose deliberately rather than guess.6 min guide