PDF Compressor

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document.pdf0 KB
Compression Settings
Advanced Options▼
Processing your PDF...
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Note: This tool performs client-side PDF optimization. For complex PDFs with many embedded fonts or high-resolution images, results may vary. All processing happens in your browser - your files are never uploaded to any server.

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What is PDF Compressor

PDF Compressor reduces file size so your documents are easier to share, store, and upload. Need to email a large PDF under an attachment limit or speed up downloads without re‑creating the file? The free PDF Compressor by FlexiTools.io lets you pick a quality mode, adjust image DPI, convert to grayscale, and remove metadata — all in your browser. In the next 60 seconds, you can drag in a PDF (up to 50 MB), choose Balanced, Maximum, or Quality, toggle Advanced Options, click Compress PDF, and download the smaller result.

How to Use Our PDF Compressor

  1. Add your file
  • Drag & drop a PDF or click to browse. The file card shows its name and size. Use the ✕ button to remove it and pick another.
  1. Choose a quality mode
  • Maximum: smallest size, more visible changes. Balanced (default): best mix of size and clarity. Quality: light compression with minimal change.
  1. Open Advanced Options (optional)
  • Convert to grayscale to remove color data. Remove metadata to strip non‑content info. Set Image DPI (72–300) to downsample embedded images.
  1. Compress and download
  • Click Compress PDF. Watch the progress bar, then see Original vs Compressed size and the percent saved. Click Download Compressed PDF or Compress Another to run a new file.

Why FlexiTools.io Offers the Best PDF Compressor

Private, in‑browser processing

Your PDF is optimized on your device, not uploaded. A clear note confirms the client‑side workflow.

Clear modes, clear trade‑offs

Pick Maximum, Balanced, or Quality, with plain labels and expected reductions, so you can choose confidently.

Practical advanced controls

Grayscale, metadata removal, and DPI let you tune results for screen, web, or print needs.

Visual savings at a glance

Side‑by‑side sizes, a savings percent, and a size bar make the outcome obvious.

FlexiTools.io vs typical alternatives

  • FlexiTools.io: Client‑side compression with privacy note - Alternatives: Uploads and wait times
  • FlexiTools.io: Three quality modes + DPI - Alternatives: One‑size settings
  • FlexiTools.io: Grayscale and metadata toggles - Alternatives: Hidden or no advanced options
  • FlexiTools.io: Simple “Compress” flow - Alternatives: Multi‑page wizards

A Deeper Look at PDF Compression and Smart Settings

PDFs carry more than what you see on the page. Many files include high‑resolution photos, color profiles, thumbnails, embedded fonts, and metadata. Shrinking a PDF means reducing the weight of those parts without breaking the document. That is exactly what the options in this tool target.

Quality mode

  • Maximum applies more aggressive image recompression and downsampling. It is ideal when size is your top priority and minor quality loss is acceptable.
  • Balanced keeps images looking good while trimming substantial weight. It’s the best first choice for sharing and archiving.
  • Quality makes light changes. Use it when the original is already optimized or you need to preserve detail, but still want a smaller file.

Image DPI

  • DPI (dots per inch) controls how embedded images are downsampled. Lower DPI reduces pixels, and fewer pixels mean fewer bytes.
  • For on‑screen reading, 72–96 DPI often looks fine. For general documents with photos, 150 DPI is a strong baseline. For print or detailed graphics, 200–300 DPI preserves more detail at a higher size.
  • The biggest wins usually come from DPI, not from squeezing quality alone. If you’re aiming for a target size, try a sensible DPI first, then adjust the mode.

Grayscale

  • Converting to grayscale removes color channels. That can shave many megabytes from photo‑heavy reports and scans.
  • It works best on documents where color isn’t essential—drafts, text‑heavy PDFs, or black‑and‑white scans. If your file has colored charts or brand elements, preview after compression to confirm they still read well.

Remove metadata

  • PDFs can store author, creation date, tool info, and embedded thumbnails. Removing metadata cuts a little size and improves privacy for public sharing.
  • Some workflows rely on metadata; if you’re unsure, compress once with it on and once with it off, then decide.

What actually changes inside the file?

  • Embedded images are recompressed (for example, fewer JPEG artifacts at higher quality vs. more artifacts at lower quality) and downsampled to the DPI you choose.
  • Optional color conversion and metadata cleanup reduce non‑essential data.
  • Fonts and text are not rasterized; the tool focuses on image optimization and lightweight cleanup. For complex PDFs with many embedded fonts or unusual objects, results can vary—verify after download.

Why does this matter? Smaller PDFs open faster and are easier to email or upload. Even a 30–50% reduction can make a large report fit a strict attachment limit. If you care about overall performance on the web, image size and format choices are core factors—see MDN’s guidance on image optimization and Google Search Central’s notes on using modern image formats. Although those resources discuss webpage images, the same principle holds for PDFs: fewer pixels and efficient encoding cut file size.

Choosing the right settings

  • Start with Balanced at 150 DPI. Review the result at 100% zoom. Does text look crisp? Do photos look fine?
  • If you need more savings, switch to Maximum or lower the DPI. For black‑and‑white documents, try Grayscale.
  • If the file includes sensitive info in metadata, keep Remove metadata checked.

A quick rule of thumb: resize first (DPI), then adjust quality mode. Why fight for a few megabytes with heavy compression if you can remove thousands of extra pixels you’ll never display?

What about edge cases?

  • Scanned documents: Often image‑only. Grayscale + 150 DPI can dramatically reduce size while keeping text readable.
  • Presentation decks exported to PDF: Lots of large slides and photos. Try 96–150 DPI and Balanced.
  • Print‑ready PDFs: Use Quality mode and 200–300 DPI; avoid Grayscale if color matters.

In short, small moves—lower DPI, grayscale, metadata off—do most of the work. If a setting hurts clarity, step back one notch and re‑run. That quick loop nails the sweet spot fast. Isn’t a file that opens quickly and still looks sharp exactly what you want?

Pro-Tips for Getting the Most Out of PDF Compression

  • Pick settings by destination: screen (72–96 DPI), general sharing (150 DPI), print (200–300 DPI). Start with Balanced.
  • Use Grayscale for scans and text‑first files; keep color for charts, brand assets, and photos that matter.
  • If your goal is a strict size cap, reduce DPI first, then switch to Maximum mode if needed.
How big of a PDF can I compress?
You can upload a single PDF up to 50 MB. If your document is larger, split it into sections and compress each part, or reduce image sizes in the source before exporting to PDF.
Are my files uploaded to a server?
No. Compression runs in your browser. The note under the results confirms client‑side optimization. This keeps your document private while you test settings.
Which quality mode should I choose?
Start with Balanced for most documents. If the result needs to be smaller, try Maximum or lower the DPI. If you need to preserve detail—charts, fine lines—use Quality and a higher DPI.
What does Image DPI do, and will text get blurry?
DPI downscales embedded images. Text usually stays crisp because it remains text, not an image. Always review the compressed PDF at 100% zoom—lower DPI can soften photos, not vector text.
Can I remove color or metadata?
Yes. Check Convert to grayscale to remove color channels and shrink photo‑heavy files. Keep Remove metadata on to strip non‑content info and save a bit more space. If your workflow needs metadata, uncheck it and compare.