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Compress PDF Without Losing Quality

Every compression removes some data, but the word quality is doing a lot of work in this phrase.

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Adjustable compression levels for fine control

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Text and vectors stay sharp regardless of setting

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Low compression preserves image quality visibly

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No watermarks, no file size limits

Cost: Free forever
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Drop the PDF Compressor into any page — blog post, product docs, intranet, school portal — with a single line of HTML. Your visitors get the full tool, processed entirely in their browser. No backend, no uploads, no signup.

Files stay 100% in the visitor's browser
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Embed code

<iframe
  src="https://www.fixtools.io/pdf/pdf-compressor?embed=1"
  width="100%"
  height="780"
  frameborder="0"
  style="border:0;border-radius:16px;max-width:900px;"
  title="PDF Compressor by FixTools"
  loading="lazy"
  allow="clipboard-write"
></iframe>

<iframe
  src="https://www.fixtools.io/pdf/pdf-compressor?embed=1"
  width="100%"
  height="780"
  frameborder="0"
  style="border:0;border-radius:16px;max-width:900px;"
  title="PDF Compressor by FixTools"
  loading="lazy"
  allow="clipboard-write"
></iframe>

Attribution-friendly: a small "Powered by FixTools" link appears in the embed footer.

What "quality loss" in PDF compression actually means technically

PDF compression acts almost exclusively on embedded raster images. Text, lines, shapes, and gradients are stored as mathematical vectors and are unaffected regardless of compression setting. When a PDF is compressed, embedded JPEG or uncompressed bitmap images are re-encoded at a lower quality factor or resampled to a lower pixel density. JPEG quality in PDF compression is measured on a scale of 1 to 100. A typical print-quality PDF stores JPEG images at quality 80 to 95 and 150 to 300 DPI. Medium compression in FixTools re-encodes those images at around quality 60 to 70 and 96 DPI. High compression drops to approximately quality 40 to 50. Below quality 50, JPEG blocking artefacts become visible when zooming in to 150 percent or more. At normal 100 percent zoom on a 1080p or Retina display, quality 60 is visually indistinguishable from quality 90 for most photographic content, which is exactly why JPEG 60 is the sweet spot the web has settled on for hero images.

The phrase without losing quality is therefore technically inaccurate when applied to image content: lossy compression always removes some image data. The precise meaning is without visible quality loss at the intended viewing or printing conditions. For PDFs read on screen at 100 percent zoom, a 96 DPI image is sufficient because most displays render at 72 to 110 PPI. An image stored at 300 DPI in a PDF delivers no visual benefit at 100 percent screen zoom; those extra pixels are discarded by the renderer anyway. For printing on a standard office laser or inkjet at 600 DPI, a 96 to 120 DPI embedded image is still sufficient because the printer interpolates pixel data between source pixels. Professional-quality print, such as commercial offset printing at 300 DPI on coated stock, requires the original 300 DPI image data to be preserved, which is why a print-bound PDF should not be compressed.

There is, however, a fully lossless layer of compression that applies to every PDF regardless of setting. Stripping unused metadata fields (document properties left over from the authoring app, hidden author comments, tracking GUIDs), subsetting embedded fonts so only the characters actually used are stored rather than the full font file, removing duplicate internal objects, and re-encoding the PDF cross-reference table with a more efficient stream filter all reduce file size without touching a single pixel. On a typical exported Word document or PowerPoint deck, these lossless operations alone can cut 10 to 30 percent of the size before any image re-encoding begins. FixTools applies these passes first, so even at the low setting you get meaningful size reduction with literally zero pixel change to images.

On the lossy side, the image codec choice matters as much as the quality factor. JPEG remains the default for photographic content because every PDF reader supports it. JBIG2, a codec designed for monochrome scanned text, can compress a black-and-white scan to a fraction of the size of an equivalent JPEG without visible quality loss on text characters, which is why it is the go-to format for scanned book archives. JPEG2000 supports higher quality at smaller sizes than baseline JPEG but is not universally supported across older PDF viewers, so FixTools sticks with JPEG for compatibility. Perceptual quality metrics such as SSIM and PSNR show that a JPEG quality 60 image scores within a couple of percentage points of the original on most photographic content at normal viewing distance, which matches the visual experience.

For most users, the medium compression setting in FixTools delivers no perceptible quality change for PDFs intended for screen use, email, or office printing. Low compression is appropriate when the document contains fine detail such as engineering drawings, architectural schematics, or medical imaging where small features must remain distinguishable at high zoom. High compression is appropriate when file size is the primary concern and the PDF will be viewed only on screen at normal zoom, such as a marketing handout shared digitally or a WhatsApp document. The choice is not between quality and compression; it is between which viewing conditions matter most for each specific document, and how much of the original's image fidelity is needed at those conditions.

JPEG compression (Wikipedia)PDF image encoding (Adobe PDF reference)

How to use this tool

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Use low or medium compression for documents with important photographs or fine diagrams. Use high compression for text-heavy documents or any PDF that will only be viewed on a screen at normal zoom.

How It Works

Step-by-step guide to compress pdf without losing quality:

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Open the PDF Compressor
Visit the FixTools PDF Compressor in your browser of choice on desktop or mobile. There is no installer, sign-up, or in-app purchase prompt, and every compression setting is unlocked by default. The tool loads in a few seconds because the entire compression engine is a static JavaScript bundle delivered from the CDN, not a server-side process you need an account to access.
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Upload your PDF
Drag and drop your file onto the upload area or click the panel to open the system file picker. The original file remains on your device untouched; only an in-memory copy is read by the browser for compression. The interface displays the original file size and the page count once the file is loaded, which gives you a benchmark to compare against the compressed result.
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Choose the right compression level
Select low for documents where image clarity at close zoom matters, such as engineering drawings, medical scans, photography portfolios, or architectural schematics. Choose medium for the typical office document destined for email or screen reading, which is the right answer roughly 80 percent of the time. Use high only for screen-only documents where size reduction matters more than image fidelity, such as marketing handouts or WhatsApp shares.
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Compress and preview
Compress the PDF and open the output in your default PDF viewer (Preview on macOS, Adobe Reader or Edge on Windows, the Files app on iPhone). Zoom to 150 percent on any images and at any diagrams or scanned text to assess quality at close range. Text and vector elements should be identical to the original; only photographic regions will show any change, and at medium the change is usually undetectable without a side-by-side comparison.
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Recompress if needed
If quality at 150 percent zoom is insufficient for your needs, return to the tool with the original uncompressed file and pick a lower compression setting. Never recompress an already-compressed PDF, because each lossy pass stacks artefacts. Always start from the original source. Keep the uncompressed master file as your archive copy, and treat each compressed variant as a single-use delivery file for a specific recipient or channel.

Real-world examples

Common situations where this approach makes a real difference:

An interior designer compresses a 35-page portfolio PDF from 28MB to 6.2MB at medium compression. Client photographs of completed rooms remain sharp at 100 percent screen zoom on a typical 1440p laptop display. At 200 percent zoom a slight softening is visible in wood grain textures and curtain fabric weave, but the designer finds this acceptable for client email review where the file is glanced at on a phone or tablet. For print submissions to design awards on coated A3 stock, she keeps the uncompressed original archived in iCloud Drive.

A medical school compresses lecture slides containing histology microscopy images. The original 18MB PDF compresses to 4.8MB at low compression, which is the right setting because staining detail must remain visible at 150 percent zoom when students identify cell structures during revision. High compression visibly blurs the eosin and haematoxylin staining boundaries, which is unacceptable for educational use. The lecturer publishes the low-compression version to the LMS and notes in the syllabus that it is the canonical study copy.

A restaurant owner compresses a 12-page menu PDF with food photography from 8.5MB to 1.9MB at medium compression. On mobile screens where the menu is most often viewed when guests scan a table QR code, the food photos look identical to the original. On a 4K monitor at 200 percent zoom some JPEG blocking is visible in sauce reflections, but the practical viewing context is a five-inch phone screen at 100 percent zoom, so medium is the right balance between size and visible quality.

An engineering firm sends CAD-exported PDF drawings in project update emails. The original 22MB drawing set compresses to 7.4MB at low compression. Dimension annotations at 0.5mm line width remain readable at 150 percent zoom, which is critical for contractors who scale the drawings to verify clearances on site. High compression blurs fine line detail at those zoom levels because the underlying raster fallback for some hatched fills loses pixel definition, so low compression is required and the engineering team documents it as the office standard for issued drawings.

A graphic designer producing a magazine retains the uncompressed master at quality 95 JPEG 300 DPI for the offset printer and produces a separate medium-compressed copy at JPEG 65 96 DPI for the client review email. Both are generated from the same InDesign export, with FixTools handling the screen variant. The print copy is 84MB, the review copy is 9MB, and the client only ever sees the smaller file. This two-track approach is the professional pattern for any document that has both print and digital destinations.

Pro tips

Get better results with these expert suggestions:

Check the output at 150 percent zoom before sharing

Open the compressed PDF in your viewer and zoom to 150 percent on the most important images or diagrams in the document. This simulates the zoom level at which JPEG blocking artefacts first become visible to a careful viewer. If everything looks clear and edges are crisp at that level, medium or high compression is appropriate for your content. If detail is lost in shadow regions, gradients, or fine text on coloured backgrounds, switch to low compression and recompress from the original.

Keep the original for any document that may be printed professionally

Office and home printing at 600 DPI interpolates compressed images acceptably because the printer fills in detail between source pixels. Professional offset print at 300 DPI on coated stock, however, requires the original image data because the half-tone screen reveals JPEG artefacts that the eye cannot see on screen. If there is any chance the PDF will be sent to a commercial printer later, keep the uncompressed original archived and only share the compressed version for digital review.

Vector diagrams survive any compression setting

Charts, graphs, technical drawings, and text exported from PowerPoint, Word, Canva, Figma, Illustrator, or InDesign as vectors are stored mathematically in the PDF and are not affected by any compression setting. Only embedded photographs and scanned raster content degrade. If your PDF is mostly charts, text, and line art, even high compression will not produce visible quality loss, because there are essentially no pixels for the lossy stage to recompress.

Strip metadata for a small lossless gain

PDFs exported from Word and PowerPoint often contain author name, company name, document tracking GUIDs, hidden review comments, and revision history that bloat the file without contributing to its visible content. FixTools removes unused metadata as part of every compression run, including at the lowest setting, which gives you a few percent of file size back without touching a single pixel. This is the cleanest kind of compression: literally no loss of anything you can see in the document.

Re-export at screen quality before compressing for best results

If the source application (Word, Canva, InDesign, Affinity Publisher) offers an optimise for screen or web quality export option, use that before compressing in FixTools. The screen-quality export reduces image DPI at the source using the application's knowledge of which assets are decorative vs critical, leaving FixTools less work to do and producing a cleaner result at a given quality setting than compressing a heavy print-quality export aggressively in one step.

FAQ

Frequently asked questions

For images, technically no: lossy compression always removes some pixel data. But for PDFs viewed on screen at 100 percent zoom or printed on a standard office printer, the quality loss at medium compression is not visible to the human eye at normal viewing distance. The distinction matters: truly lossless quality is only necessary for commercial offset printing or archival copies. For everyday use, medium compression produces an output that is indistinguishable from the original under normal viewing conditions, and the lossless pass (metadata, font subsetting) is genuinely lossless for what you actually see.

Use low or medium compression for documents where photograph quality matters. Low compression reduces file size by 20 to 40 percent while preserving image clarity at close zoom up to 200 percent or so. Medium compression achieves 40 to 60 percent reduction with photos remaining visually sharp at standard screen viewing distances and zoom levels. High compression is best reserved for text-heavy documents or screen-only handouts where the photos are decorative rather than the substance of the document, such as a stock-photo header on a newsletter.

No, with one footnote. Text in vector-based PDFs (exported from Word, Pages, Google Docs, InDesign) is stored as vector character outlines drawn from an embedded font, not as pixel images. Compression does not affect text sharpness, readability, or searchability at any compression level. Even at maximum compression, this text remains perfectly sharp and fully selectable. The footnote: scanned PDFs where the pages are actually photographs of text are raster, and aggressive compression can blur the text. For those, use low compression or OCR the file first.

Lossy compression (used for embedded images) permanently removes pixel data to reduce file size, applying algorithms such as JPEG re-encoding at lower quality factors and DPI resampling. Lossless compression removes only structural redundancy without touching any image data, such as stripping empty metadata fields, unused font subsets, duplicate internal objects, and inefficient stream encodings. FixTools applies both in sequence: lossless cleanup first, then lossy image re-encoding tuned to the chosen level. Choosing a lower setting minimises the lossy component while still applying the full lossless cleanup.

Font subsetting is a lossless optimisation. When a PDF embeds a font such as Helvetica or Calibri, by default it can store the entire font file, including thousands of glyphs you never use. Subsetting removes the unused glyphs and keeps only the characters that actually appear in the document, which can save hundreds of kilobytes per font. Text remains pixel-perfect because the glyph data for every character you actually use is preserved exactly. FixTools subsets fonts automatically as part of the lossless pass at every compression level.

FixTools uses baseline JPEG for compatibility because every PDF reader on every platform supports it. JBIG2, an excellent codec for scanned black-and-white text, and JPEG2000, which offers better compression than baseline JPEG at the same visual quality, are supported by Adobe Acrobat and modern readers but not by every viewer in the wild. For maximum compatibility across email recipients, government portals, and older devices, sticking with baseline JPEG avoids the rare but frustrating case where the recipient cannot open the file. The size penalty vs JPEG2000 is small in practice.

For standard office printing (600 DPI laser, 300 DPI inkjet), medium compression produces printed output that is visually identical to the original to the unaided eye. The printer interpolates between pixels when the image DPI is lower than the print DPI, which fills in detail effectively. For high-end commercial printing on coated stock with a 150 to 175 line per inch half-tone screen, preserve the original uncompressed file and share only the compressed copy for digital review. Always send the print-quality master to the printer, never a compressed proof.

Yes. After downloading the compressed PDF, open both the original and the compressed version side by side in your PDF viewer (Preview on macOS supports this with two windows; Adobe Reader on Windows allows split view). Zoom to 150 percent on the same image area in each file and compare. The side-by-side view at that zoom level shows exactly what the compression has changed. For most content, medium compression shows no perceptible difference at this comparison zoom on a typical office monitor.

Low compression typically produces a file 20 to 40 percent larger than medium compression for the same document. For example, a 10MB original might compress to 3.5MB at medium and 5.5MB at low. The extra size buys noticeably sharper images at close zoom and preserves more subtle gradient detail in photos. Whether the size difference is acceptable depends on your target size limit and how closely recipients will examine images in the document. For a portfolio reviewed at large screen, low is worth it; for an email attachment, medium is plenty.

FixTools generates the compressed file in your browser and prompts you to download it. After downloading, open it in any PDF viewer to assess quality at the zoom levels your recipients will actually use. If the result does not meet your needs, re-upload the original (never the already-compressed copy, since stacking lossy compression amplifies artefacts) and choose a different compression level. The original file on your device is never modified by FixTools, so it remains the safe starting point for any number of recompression attempts at different settings.