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Comparisons

Best Free PDF Compressors in 2025 — Compared

June 22, 20259 min read

Finding the Right Free PDF Compressor

There are dozens of PDF compression tools available online, and most of them claim to be the best. But when you actually need to compress a PDF — for a job application, email attachment, or document upload — which tool should you use?

We tested five of the most popular free PDF compressors in 2025 with real-world files: a scanned certificate (2.4MB), a text-heavy report (5.1MB), and a presentation PDF with images (12MB). Here is what we found.

The 5 Tools We Compared

  • Compressly — compressly.live
  • iLovePDF — ilovepdf.com
  • SmallPDF — smallpdf.com
  • Adobe Acrobat Online — adobe.com/acrobat/online/compress-pdf
  • PDF24 — tools.pdf24.org

    • Let us look at each one in detail.

    1. Compressly

    Website: compressly.live

    How it works: Upload your PDF, choose a compression level (light, medium, or strong), and download the compressed file. Processing happens in the browser.

    Pros:

  • Completely free with no daily limits
  • No account or sign-up required
  • Works fully in the browser — files are not uploaded to a server
  • Clean mobile experience — works well on Android and iOS
  • Fast processing, even on slower devices
  • Also offers image compression and format conversion
  • No watermarks on output files

    • Cons:

  • Requires an internet connection to load the tool (though processing is local)
  • No desktop app for offline use
  • No advanced options like DPI control or individual page settings

    • Best for: Students and professionals who need quick, free, no-hassle compression — especially on mobile devices. Ideal for government form uploads and email attachments.

    Compression results:

  • Scanned certificate: 2.4MB reduced to 185KB (92% reduction)
  • Text report: 5.1MB reduced to 1.2MB (76% reduction)
  • Presentation PDF: 12MB reduced to 2.8MB (77% reduction)

    • 2. iLovePDF

    Website: ilovepdf.com

    How it works: Upload your PDF, choose extreme, recommended, or less compression, and download. Files are uploaded to their servers for processing.

    Pros:

  • Wide range of PDF tools beyond compression (merge, split, convert, edit)
  • Decent compression quality
  • Supports batch processing
  • Available as a desktop app (paid)
  • Well-known and widely used

    • Cons:

  • Free plan limits you to a certain number of tasks per day
  • Files are uploaded to their servers — privacy concern for sensitive documents
  • Shows ads and upsell prompts on the free version
  • Requires sign-up for some features
  • Mobile experience has occasional pop-ups

    • Best for: Users who need a full suite of PDF tools and do not mind the daily limits or server-side processing.

    Compression results:

  • Scanned certificate: 2.4MB reduced to 210KB (91% reduction)
  • Text report: 5.1MB reduced to 1.4MB (73% reduction)
  • Presentation PDF: 12MB reduced to 3.1MB (74% reduction)

    • 3. SmallPDF

    Website: smallpdf.com

    How it works: Upload, compress, download. SmallPDF processes files on their servers and offers two compression modes: basic and strong (strong requires a paid plan).

    Pros:

  • Very clean, professional interface
  • Good compression quality on the free tier
  • Offers many PDF tools (merge, split, convert, sign, edit)
  • Available as desktop and mobile apps
  • Integration with Google Drive and Dropbox

    • Cons:

  • Free plan limited to 2 tasks per day — this is the biggest drawback
  • Strong compression (Pro) requires a paid subscription ($9/month)
  • Files uploaded to their servers
  • The free tier feels restrictive with frequent upgrade prompts
  • Daily limit resets are unpredictable

    • Best for: Occasional users who only need to compress one or two files and do not mind the strict daily limit. Power users will hit the paywall quickly.

    Compression results (free/basic compression):

  • Scanned certificate: 2.4MB reduced to 420KB (83% reduction)
  • Text report: 5.1MB reduced to 2.1MB (59% reduction)
  • Presentation PDF: 12MB reduced to 5.2MB (57% reduction)

    • *Note: SmallPDF's free tier uses basic compression only. Strong compression results would be better but require a paid plan.*

    4. Adobe Acrobat Online

    Website: adobe.com/acrobat/online/compress-pdf

    How it works: Upload your PDF, Adobe compresses it on their servers, and you download the result. Offers three compression levels: high, medium, and low.

    Pros:

  • Built by the creators of the PDF format
  • Reliable compression quality
  • Professional output
  • Integrates with Adobe ecosystem (Creative Cloud, Document Cloud)
  • Trusted brand name

    • Cons:

  • Free plan allows limited compressions per day
  • Requires an Adobe account to download results
  • Files are uploaded to Adobe's servers
  • Interface can be slow, especially on mobile
  • Pushes you toward Acrobat Pro subscription ($19.99/month)
  • The online tool sometimes redirects to the desktop app download page

    • Best for: Users already in the Adobe ecosystem who have an Adobe account. Not ideal for quick one-off compressions due to the sign-in requirement.

    Compression results:

  • Scanned certificate: 2.4MB reduced to 280KB (88% reduction)
  • Text report: 5.1MB reduced to 1.5MB (71% reduction)
  • Presentation PDF: 12MB reduced to 3.4MB (72% reduction)

    • 5. PDF24

    Website: tools.pdf24.org

    How it works: Upload your PDF, choose compression settings (DPI, image quality, color options), and download. PDF24 offers a surprising amount of control for a free tool.

    Pros:

  • Completely free with no daily limits
  • No account required
  • Offers advanced settings (DPI control, image quality, grayscale conversion)
  • Very comprehensive PDF toolset (40+ tools)
  • Available as a free desktop app for Windows
  • No watermarks

    • Cons:

  • Files are uploaded to their servers for processing
  • Interface is functional but feels dated compared to competitors
  • Mobile experience is clunky — the site is not optimized for small screens
  • Advanced settings can be confusing for non-technical users
  • Desktop app is Windows-only
  • Processing can be slow for large files

    • Best for: Technical users who want fine-grained control over compression settings and do not mind the dated interface. The free desktop app is excellent for Windows users who process many PDFs.

    Compression results:

  • Scanned certificate: 2.4MB reduced to 195KB (92% reduction)
  • Text report: 5.1MB reduced to 1.3MB (75% reduction)
  • Presentation PDF: 12MB reduced to 2.9MB (76% reduction)

    • Side-by-Side Comparison

    | Feature | Compressly | iLovePDF | SmallPDF | Adobe | PDF24 |

    |---|---|---|---|---|---|

    | Price | Free | Free (limited) | Free (2/day) | Free (limited) | Free |

    | Sign-up needed | No | For some features | No | Yes | No |

    | Daily limits | None | Yes | 2 tasks/day | Yes | None |

    | Mobile friendly | Excellent | Good | Good | Poor | Poor |

    | Privacy (local processing) | Yes | No | No | No | No |

    | Compression quality | Very good | Good | Good (basic) | Good | Very good |

    | Advanced settings | No | No | No (free) | No (free) | Yes |

    | Extra PDF tools | Basic | Many | Many | Many | Many |

    | Watermarks | No | No | No | No | No |

    | Offline mode | No | Paid app | Paid app | Paid app | Free (Windows) |

    Which Tool Should You Use?

    Here is our recommendation based on your situation:

    Choose Compressly if:

  • You want free compression without limits or sign-ups
  • You care about privacy (files stay in your browser)
  • You primarily use a mobile phone
  • You need to compress files for Indian government portal uploads
  • You want the simplest, fastest experience

    • Choose iLovePDF if:

  • You need multiple PDF tools (merge, split, convert) in addition to compression
  • You do not mind daily limits on the free tier
  • You are okay with files being processed on external servers

    • Choose SmallPDF if:

  • You only compress PDFs occasionally (the 2/day free limit is enough)
  • You value a polished, professional interface
  • You are willing to pay for strong compression

    • Choose Adobe Acrobat Online if:

  • You already have an Adobe account
  • You use other Adobe products
  • Brand trust is important to you

    • Choose PDF24 if:

  • You want advanced control over compression settings
  • You are on Windows and want a free desktop app
  • You are technically comfortable adjusting DPI and quality settings

    • The Bottom Line

    For most people — especially students and professionals in India who need to compress PDFs for form uploads, job applications, and email — [Compressly](/) offers the best combination of simplicity, privacy, and value. It is completely free, has no daily limits, requires no sign-up, and works well on mobile devices.

    If you need a broader PDF toolkit with features like merging, splitting, and editing, iLovePDF or PDF24 are solid free options with the trade-off of server-side processing.

    And if you are willing to pay for premium features, SmallPDF offers the most polished experience at $9/month.

    Try Compressly's PDF Compressor today and see the difference for yourself — no sign-up required.

    Ready to Compress Your Files?

    Try Compressly free - no signup required.

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