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Nitro PDF Pro alternatives · PDF Editors

Open-source alternatives to Nitro PDF Pro

Nitro PDF Pro is not described as open source on its own site. 4 of the 45 other PDF editors in this directory are open source, according to their own sites.

Nitro PDF Pro is a paid product with a free trial, starting at $15 per user / month, billed annually. All of them are free or have a free plan.

4 tools · Listings checked up to Nov 13, 2026 · Where the facts come from

How each one differs from Nitro PDF Pro

  1. Stirling PDF

    Open-source PDF editor you can run on your own machine or server

    • Stirling PDF starts at $99 per month for 100 users (Team). Nitro PDF Pro starts at $15 per user / month, billed annually.
    • Stirling PDF has a free plan. Nitro PDF Pro does not, though it has a free trial.
    • Only Stirling PDF lists a Linux app.
    • Only Nitro PDF Pro lists an iOS app.
    Stirling PDF pricing and details

  2. PDFsam

    Split and merge PDFs offline, with paid Visual and Enhanced editions

    • PDFsam starts at $34.90 per user / year (PDFsam Visual); PDFsam Basic is free. Nitro PDF Pro starts at $15 per user / month, billed annually.
    • PDFsam has a free plan. Nitro PDF Pro does not, though it has a free trial.
    • Only PDFsam lists a Linux app.
    • Only Nitro PDF Pro lists a web app.
    PDFsam pricing and details

  3. Skim

    Free PDF reader and note-taker for Mac, built for papers

    • Skim is free. Nitro PDF Pro starts at $15 per user / month, billed annually.
    • Skim has a free plan. Nitro PDF Pro does not, though it has a free trial.
    • Only Nitro PDF Pro lists a web app.
    • Only Nitro PDF Pro lists Windows and iOS apps.
    Skim pricing and details

  4. SumatraPDF

    Small, free PDF, eBook and comic reader for Windows

    • SumatraPDF is free. Nitro PDF Pro starts at $15 per user / month, billed annually.
    • SumatraPDF has a free plan. Nitro PDF Pro does not, though it has a free trial.
    • Only Nitro PDF Pro lists macOS and iOS apps.
    • SumatraPDF is open source, according to its own site.
    SumatraPDF pricing and details

Common questions

Is there an open-source alternative to Nitro PDF Pro?

Yes. Stirling PDF, PDFsam, Skim and SumatraPDF are open source, according to their own sites.

Is Nitro PDF Pro open source?

Nitro PDF Pro is not described as open source on its own site. The listing was checked on Oct 18, 2026 against the pages it cites.

When was this checked?

Each listing shows its own date. On this page they run from Oct 18, 2026 to Nov 13, 2026. Vendors change prices and plans without notice, so confirm on their site before you buy.

This page is built from the listings. A tool is here because its listing says so, and the order is how close each is to Nitro PDF Pro: the alternatives its listing names first, then the tools that share the most features with it.