Reduce PDF file size by optimizing structure.
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Large PDF files cause real problems: email attachment limits reject them, upload forms refuse them, and slow connections make sharing painful. This tool addresses that by optimizing the file's structure and stripping metadata - a completely lossless operation, since it never re-encodes images or fonts.
That also means the size reduction is genuinely variable: a form or contract with a lot of embedded metadata can shrink noticeably, while an already-optimized or image-heavy PDF may see little to no change - the tool tells you honestly when that happens instead of showing a misleading number.
This PDF compressor reduces file size through lossless structural optimization - stripping embedded metadata (title, author, subject, keywords, producer, creator) and applying object-stream compression to the file's internal structure. It does not re-encode images or fonts, so visual quality is completely unchanged; the size reduction you get depends entirely on how much metadata and structural overhead the original file carries.
Choose the PDF file you want to compress.
We optimize the PDF structure to reduce file size.
Download the compressed PDF instantly.
Upload your PDF to see its current file size displayed immediately.
Click Optimize PDF to strip embedded metadata and apply object-stream compression - the tool shows the new size and percentage reduction right after.
If the file didn't shrink, the tool shows "No size reduction - content could not be further optimized" instead of a misleading percentage.
Click Download Optimized PDF to save the result - the filename gets an "_optimized" suffix automatically.
Best For
Input
A PDF exported from word-processing software with embedded author/title/producer metadata and many internal objectsResult
A noticeably smaller file, with the reduction shown as a percentageStripping metadata and consolidating internal objects into compressed streams has real content to work with in this kind of file.
Input
A PDF made up mostly of high-resolution scanned page imagesResult
"No size reduction - content could not be further optimized"Since the tool never re-encodes images, a file whose size is dominated by image data has little for the structural optimization to remove.
Strip the author, title, and producer fields from a PDF you're about to share externally.
Run PDFs exported from office software - which often carry a lot of embedded metadata - through the optimizer for a quick, lossless size reduction.
Try this tool first before reaching for a lossy image-recompression tool, since it carries zero quality risk.
Problem
Solution
Since this tool never re-encodes images, a scanned or photo-heavy PDF - where most of the size is image data - will shrink little or not at all.
Problem
Solution
This is a structural, metadata-stripping optimization only - it's a different operation from an image-recompression tool, and won't produce the dramatic size drops those tools can.
Problem
Solution
There's one fixed optimization pass - no low/medium/high levels and no "compress to 100KB" option.
Problem
Solution
Along with the size optimization, the tool blanks the PDF's title, author, subject, keywords, producer, and creator fields - re-add them afterward in another tool if you need to keep that information.
Since this optimization never touches image quality, it's a safe first step - if the reduction isn't enough, then consider a tool that re-compresses images.
If you just want to remove author/title/producer information from a PDF before sharing it, running it through this tool accomplishes that as a side effect.
A short text PDF or a scan-heavy document has little structural overhead to remove - the honest "no reduction" message is expected in that case, not a bug.
This is a lossless, structure-only optimization - it never reduces image quality, resolution, or font data, so it can't produce the large reductions a lossy image-recompression tool can.
There's a single fixed optimization - no low/medium/high or custom-quality settings.
You can't specify a target size like 100KB or 1MB - the output size is whatever the lossless optimization produces.
If most of a PDF's size comes from embedded images, this tool's metadata-and-structure optimization has little to remove.
Title, author, subject, keywords, producer, and creator fields are blanked as part of the optimization - this can't be selectively disabled.
Both aim to shrink a PDF, but they work on completely different parts of the file.
| This Tool (Structure-Only) | A Lossy Image-Recompression Tool | |
|---|---|---|
| What it changes | Metadata fields and internal object structure only | Re-encodes embedded images at a lower quality/resolution |
| Quality impact | None - completely lossless | Some visual quality loss, usually not visible at moderate settings |
| Best for | Metadata-heavy or complex-structure PDFs; a safe first pass | Image-heavy or scanned PDFs that need a large size reduction |
Which should you use?
If this tool's result isn't small enough for an image-heavy file, that's expected - it isn't designed to touch image data at all, and a different, lossy tool would be needed for that kind of reduction.
The most common question is whether compression reduces quality. It doesn't - this tool only strips metadata and optimizes the PDF's internal structure using object streams; it never re-encodes images or fonts. That also means it won't dramatically shrink an image-heavy PDF - the FAQ below explains what to expect and why some files barely shrink at all.
No. This tool only removes embedded metadata (title, author, subject, keywords, producer, creator) and applies object-stream compression to the file's internal structure - it doesn't re-encode images or fonts, so visual quality is completely unchanged.
It depends on the PDF. Files with a lot of embedded metadata or many separate internal objects can shrink noticeably from the structural optimization. Image-heavy PDFs - where most of the file size is the images themselves - will see minimal or no reduction, since images aren't re-compressed.
If a PDF is already well-optimized, or its size mostly comes from embedded images and fonts rather than metadata or document structure, there's little for this tool to remove. The tool shows "No size reduction" in that case rather than a misleading percentage.
No. This tool performs one fixed optimization pass and doesn't offer target file size or compression level options - the result is whatever size the structural optimization produces.
No. This tool processes your PDF entirely in your browser using the client-side pdf-lib library - your file is never uploaded to any server. You can verify this yourself by opening your browser's DevTools Network tab before compressing.
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