Best Free PDF Compressors 2026: 6 Options Compared

Shrinking a PDF is usually for one of two reasons: an email or upload form has a size cap, or you are archiving scans. The free online compressors all work the same way, you upload, they squeeze, you download, and the differences are in the limits and in what happens to your file. iLovePDF and Smallpdf cap the number of compressions per task or per day on their free plans, Sejda allows 3 tasks per hour, and PDF24 states no limit. If the document is confidential, such as a contract or tax return, a desktop route avoids uploading it anywhere: Stirling PDF can run on your own machine or server, and PDFgear compresses locally in its desktop app. Compression always trades quality for size, because scanned pages are images and shrinking them means lowering their resolution, so keep the original and check the result before sending. If a file is still too large after one pass, splitting it is often better than a second round of compression. The six tools below all have a free way to compress PDFs, with the limit that applies to each noted so you can see which one will actually fit your file.

PDF24 Tools

Online tools described as 100% free with no paid plan or usage limit stated, plus a desktop app. The simplest choice when you just need a file smaller today.

Price: Free (Online PDF tools described on the page as 100% free; no paid plan or usage limit stated) (PDF24 Tools pricing, checked 2026-10-23).

Platforms and license: Web browser, Windows. Proprietary freeware.

Best for: Occasional compression with no sign-up.

iLovePDF

The free Basic plan limits batches, for example 2 compressions per task, so it handles single files well but not folders. Premium is $5 a month billed annually.

Price: Free (Basic free plan: limited tools; batch limits per task such as 25 merges and 2 compressions; 100 MB merge file size; no AI credits; web only); paid from $5 per Premium, per month billed annually (US$60 per year; US$9 billed monthly) (iLovePDF pricing, checked 2026-10-23).

Platforms and license: Web browser. Proprietary SaaS.

Best for: Single files, quick turnaround.

Sejda

The free web service allows 3 tasks per hour, documents up to 200 pages and 50 MB, with no signup. Larger files need the paid desktop or web plan.

Price: Free (Free web service: 3 tasks per hour, documents up to 200 pages and 50 MB (tool pages quote 50 or 100 MB); no signup); paid from $63 per user/year (Desktop+Web annual); Web Week Pass is a one-time US$5 for 7 days (Sejda pricing, checked 2026-10-23).

Platforms and license: Windows, Web browser. Proprietary SaaS.

Best for: Small files with a clear size limit.

Smallpdf

Free plan includes a daily cap on tasks, so it works for a couple of files a day. The exact cap could not be read on the pricing page and sources disagree.

Price: Free (Free plan with a daily cap on tasks; the number was not readable on the pricing page (third-party listings say 2 a day, the App Store listing says 1)) (Smallpdf pricing, checked 2026-10-23).

Platforms and license: Web browser, Windows, macOS, iOS, Android. Proprietary SaaS.

Best for: One or two files a day.

Stirling PDF

Open source and self-hostable, so confidential files never leave your own server. The Free plan includes 60+ tools and 1,000 monthly credits; setup is harder than a website.

Price: Free (Free plan at $0 with no card: web, desktop and self-hosted use, 60+ PDF tools and 1,000 monthly credits); paid from $99 per month (Team, 100 users) (Stirling PDF pricing, checked 2026-10-23).

Platforms and license: Web browser, Desktop app, Self-hosted (Docker). MIT, with some directories under separate licenses (open source).

Project activity: 95.2k GitHub stars · latest release v3.2.2 (Oct 24, 2026) · last commit Oct 27, 2026

Best for: Sensitive documents and bulk work.

Worth knowing: LICENSE file says MIT except app/proprietary and other directories with their own licenses. Repository README lists edit, merge, split, sign, redact, convert, OCR and compress.

PDFgear

Free for Windows and Mac with compress, merge and split tools and no sign-up. Page lists no limits or watermarks, though compression is listed among its online tools.

Price: Free (Page says completely free with no sign-up; it states no usage limits, watermark or paid plan) (PDFgear pricing, checked 2026-10-23).

Platforms and license: Windows, macOS, iOS, Android, Web browser. Proprietary freeware.

Best for: A desktop alternative to uploading.

Which one to pick

• The file is confidential and must stay on your machine: Stirling PDF
• You need to compress one file right now: PDF24 Tools
• You have a tight size limit and a file under 50 MB: Sejda
• You want one desktop app for compress, merge and edit: PDFgear