PDF Tools
Reduce a PDF's file size in your browser. Light mode preserves text and vector content while repacking the file; Balanced and Strong can raster-compress scan-like pages, but switch to structure-preserving processing when extractable text or vector drawing is detected.
Simple workflow
How to use Compress PDF
- 1Drop or choose one PDF and review its original size and page count.
- 2Choose Light for content preservation, or Balanced/Strong for an image-heavy scan.
- 3Compress locally, compare the measured result, and download only when a smaller PDF is produced.
Good to know
Frequently asked questions
Why do some PDFs shrink more than others?
Scanned PDFs often contain large page images that can be re-encoded. Text-heavy PDFs may already use compact fonts, vectors and compressed streams, leaving little safe room to reduce size.
What happens to searchable text?
Light mode preserves document structure. Balanced and Strong flatten scan-like pages to JPG images, so those results are not searchable. If substantial text is detected, the tool uses structure-preserving optimization instead.
Can the result be larger?
An attempted re-encoding can be larger than an already efficient source. In that case the tool explains the result and does not present the larger file as a successful compression.
Is the PDF uploaded?
No. Inspection, rendering, re-encoding and PDF creation happen in this browser using local workers and libraries.
Practical guide
Reduce a PDF without pretending every file compresses equally
PDF size depends on what the document contains. Scanned pages are usually large images and can often shrink through lower-resolution JPG encoding. Text, vector drawings, fonts and already-compressed images may leave much less removable data.
Light mode repacks PDF objects while preserving page content. Balanced and Strong inspect the document before rasterizing scan-like pages. When extractable text or vector drawing is detected, UtilSprout protects it by using the structure-preserving path instead. A rasterized scan remains readable but no longer contains searchable text.
Worked example
Compress a scanned handout
- Start with
- A 12-page, 18 MB PDF made from phone photos.
- Choose
- Choose Balanced and select Compress PDF.
- You get
- The browser renders and re-encodes each page, then reports the measured size. If the new PDF is not smaller, it is not offered as a successful result.
Tips for a useful result
- Keep an original copy before using lossy scan compression.
- Use Light for contracts, forms and born-digital documents with selectable text.
- Strong can soften small print; inspect several pages at normal reading zoom.
Why isn’t my PDF getting smaller?
A no-reduction result is not necessarily an application failure. PDF files can contain very different combinations of images, text, fonts and vector drawing, so the useful next step depends on what is already inside the document.
The PDF is already optimized
Some PDFs already use efficient image compression or contain little redundant data. If UtilSprout’s generated attempt is not smaller, keep the original. Recompressing the same file repeatedly does not guarantee further savings.
The PDF is mostly text or vector content
Preserving text and vector drawing can leave little room for reduction. Light uses the structure-preserving path. Balanced and Strong also switch to that path when UtilSprout detects extractable text or vector content, so a small change or no reduction can be the intended result rather than a failure.
The PDF is a scan or photo-heavy document
Image-heavy pages can often shrink because their pixels can be rendered and re-encoded. Balanced prioritizes readable pages and a reasonable reduction. Strong may make the file smaller, but images and photographed text can look softer. Inspect the result before relying on it; no percentage is guaranteed.
Compression would create a worse result
UtilSprout measures the generated file and does not offer a larger result as a successful compression. The original may already be the better file.
Choose a sensible next step
Start with the mode that matches the document, then compare the measured result and inspect important pages at a comfortable reading zoom.
| If your PDF… | Try this |
|---|---|
| Is mostly text | Try Light first. If the result is not smaller, keep the original. |
| Is scanned or photo-heavy | Try Balanced. Inspect readability before trying Strong. |
| Is already compressed | A smaller result may not be possible. Repeating compression is unlikely to help. |
| Contains searchable text you need | Avoid a mode when its on-page warning says pages may be rasterized. Keep the original as a backup. |
| Needs fewer pages rather than smaller pages | Delete or separate pages with a page-management tool. Page removal and splitting are different from compression.Remove PDF PagesSplit PDF |
Searchable text, scans and OCR
An image-only scan may already have no searchable or selectable text. PDF compression does not perform optical character recognition (OCR), so it cannot create a text layer that was not present in the source.
Rasterizing a document that does contain a searchable text layer can remove that layer. UtilSprout therefore checks for extractable text and vector painting before Balanced or Strong rasterization and uses its structure-preserving path when either is detected. Keep the warning above the Compress PDF button in mind before processing.
This tool does not verify preservation of digital signatures, interactive forms, accessibility tags or annotations. Keep the original when any of those features matter.
Limits and privacy
Files are limited to 40 MB and 400 pages. Raster compression is limited to 40 pages and bounded canvas memory; longer or text-rich documents use structure-preserving optimization.
The PDF is read, rendered and rebuilt on your device. No file content is sent to UtilSprout, analytics or a third-party conversion API.
Authoritative external sources
- Adobe Acrobat: PDF optimizer settings (external)
Explains how image downsampling, compression, fonts and document objects affect PDF size and quality.
- Adobe Acrobat: recognize text in scanned documents (external)
Explains that image-only scans need OCR to gain a searchable, selectable text layer.
Understand the details
Related reference guides
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