About PDF size reducer
Most people arrive at a size reducer because something has already said no. A government portal caps uploads at a fixed figure, a recruitment form refuses a large file, or a mail server bounces a message. A hard limit changes the task: the aim is to get under that line without making the document unreadable, not simply to choose the lowest settings. A lower DPI target can help when supported images have recoverable placement and more pixels than the intended use needs. Reducing both dimensions from 300 to 110 DPI would retain roughly one eighth of the pixels, but it can soften fine text and is not a promise of proportional byte savings. JPEG quality is a separate trade-off, and images below the DPI target may still be re-encoded. Grayscale applies only to accepted image replacements; it does not convert text or vector colours, and output image dictionaries remain DeviceRGB rather than guaranteeing single-channel savings. This page also attempts object-stream rewriting and limited metadata cleanup by default, without a metadata toggle. That cleanup targets eight standard Info keys and the catalog XMP reference, not custom entries or secure erasure of detached XMP bytes. Only a smaller complete rewrite is returned; otherwise the original bytes and metadata are retained. If the document still will not fit, check whether the recipient accepts separate parts or another delivery method.
How to PDF size reducer
- 01
Note the limit you are fighting
Find the actual maximum the form or mail server accepts and leave headroom. This tool cannot detect that limit or guarantee that a smaller file will be accepted.
- 02
Try a resolution target
Add one unencrypted PDF, up to 250 MB and 5,000 pages. Try 110 DPI, or a lower target only if the returned images remain readable at the size you need.
- 03
Compare quality and colour settings
Adjust JPEG quality separately and rerun. Try grayscale only where losing colour in supported images is acceptable; it neither converts the whole page nor guarantees a smaller file.
- 04
Check, then submit
Read the returned-file size and inspect important details before downloading. The -compressed.pdf name may still contain unchanged original bytes; split only if the receiving system accepts parts.
What this tool does
- Ordered around getting under a hard limit rather than around abstract quality settings
- Starts with a 110 DPI target and independent JPEG quality control; neither guarantees meeting a size limit
- Optional grayscale for supported image replacements, without converting text or vector colours
- Immediate size readout so you know whether you have cleared the threshold
- Nothing uploaded; one PDF at a time, with limits of 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.
- Some documents will not fit a strict limit with this method at usable quality. Splitting helps only if the recipient accepts multiple files; no-saving is not proof of optimal size.
- Accepted grayscale and JPEG image changes are irreversible. Skipped images and text or vector colours can remain unchanged, so the PDF may still contain colour.
- Embedded fonts are not subset. A text-only file can also contain other large objects, and structural rewriting or limited metadata cleanup may save little.
- Portal limits vary widely and are set by whoever runs the portal; this tool cannot detect them for you.
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 PDF size reducer
My PDF is way over the limit. What should I change first?
Try the DPI target if the file contains oversized scans or photographs, then inspect small text and detailed areas. Halving both pixel dimensions leaves one quarter of the pixels, but the byte saving depends on content and encoding. Placement must be measurable for downsampling, and only smaller supported replacements are kept. JPEG quality is independent and can also help; neither control is always the strongest.
Nothing I try gets the file small enough. What now?
This method may have reached its useful limit, but that does not establish the document's smallest possible size. Unsupported images, existing compression and the detail needed for legibility all matter. Ask whether separate parts, an excerpt or another delivery method are acceptable. If the candidate was not smaller, the download contains the original bytes rather than a larger or partially cleaned version.
Will grayscale really make that much difference?
It can change the size of supported colour images, but there is no fixed saving or guarantee of three channels becoming one. The browser applies a grayscale image filter and JPEG encoding; accepted replacements are declared DeviceRGB. A replacement is kept only if smaller, and the whole rewrite must also be smaller. Text, vector colours and skipped images are not converted, so inspect both colour and file size.
Is it safer to reduce the file here than on an upload site?
The PDF is processed locally rather than uploaded to a conversion server, which avoids that particular transfer. It does not make the output sanitized or automatically safe to share. Limited metadata cleanup is enabled here, but custom entries, page metadata and detached XMP bytes may remain, and an unchanged-original result retains all original data. Check the file and the receiving service before sending sensitive material.
Tools that pair with this one
- Compress PDFMake a PDF smaller by re-encoding its images and cleaning up its internals.
- Reduce PDF File SizeTry smaller image settings, then compare the returned size and appearance with your target.
- Compress PDF for EmailTry reducing an attachment, then check its size against both mail providers' limits.
- Split PDFCut one PDF into several documents — by range, by interval or page by page.
- PDF Size AnalyzerA byte-level breakdown of where your PDF weight actually is.
- PDF OptimizerTry structural rewriting and image compression, then check the returned file and reported saving.
Read more about this
- 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
- 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