The PDF is the one file format everybody is allowed to read and almost nobody is allowed to change. Adobe made the format an open standard years ago, and then made the editor a subscription.
Stirling PDF is what happens when someone builds the editor's toolbox and hands it out.
The best open source Adobe Acrobat alternative for most teams is Stirling PDF: MIT licensed at its core, free to run as a desktop app or on your own server with Docker, with more than 50 PDF tools and version 3.3.0 released on November 5, 2026. BentoPDF is the pick if files must never leave the browser, and PDFsam Basic is the pick for a desktop that only needs to split and merge. Adobe Acrobat Pro costs US$19.99 a month on an annual plan, or $239.88 a year prepaid (checked Nov 6, 2026).
What Stirling PDF actually is
Stirling PDF is an open source PDF application whose README lists “50+ PDF tools” to edit, merge, split, sign, redact, convert, OCR and compress files, and the repo had about 95,800 GitHub stars on Nov 6, 2026 (repo). Version 3.3.0 shipped on November 5, 2026 with installers for Windows, macOS and Linux and a server jar.
Stirling PDF runs three ways: as a personal desktop app, in the browser, or on your own server with one Docker command. The project calls itself “open-core”. The LICENSE file is MIT, and it carves out a short list of folders (the proprietary, SaaS and cloud code among them) that carry their own licences. The hosted version on stirling.com has a Free plan at $0 with 1,000 monthly automation credits, and a Team plan at $99 a month with 100 users included (checked Nov 6, 2026).
Adobe Acrobat Pro for teams is US$23.99 per licence a month on an annual plan (Nov 6, 2026). Stirling PDF's Team plan is $99 a month for 100 users, and the self-hosted version has no licence count at all.
What Adobe Acrobat costs now
Adobe Acrobat Pro costs US$19.99 a month billed on an annual commitment, $239.88 a year prepaid, or $29.99 a month with no commitment, on adobe.com on Nov 6, 2026. Acrobat Studio, which adds the AI Assistant, is $24.99 a month on the annual plan. Acrobat Pro for teams is $23.99 per licence a month, and an AI Assistant add-on for Pro is listed at $1.99 a month. Cancelling an annual plan after 14 days costs half the remaining commitment. Adobe Acrobat's sticker is honest; the cost is that it is per person, every year.
Is Adobe Acrobat free?
Adobe Acrobat Reader is free; Adobe Acrobat is not. Adobe's own Reader page says “Acrobat Reader is free to download and use without a subscription.” Reader lets you view, print, share and comment on PDFs, fill in forms and add a signature. The same page says “Text and image editing is not available in Acrobat Reader” and that editing needs an Acrobat Standard or Acrobat Pro subscription (checked Nov 6, 2026).
The open source Adobe Acrobat alternatives
Of the 149 PDF tools in the AppClap catalog (Nov 6, 2026), 10 are open source and 103 have a free tier. These four cover most of what people open Acrobat Pro for.
Stirling PDF
Stirling PDF is a full PDF toolkit with merge, split, convert, compress, OCR, redaction and signing. It is free to self-host, with a hosted Free plan and a $99 a month Team plan for 100 users (Nov 6, 2026). The core is MIT licensed, and it runs as a desktop app, in a browser or from Docker. It is best for an office that wants one shared PDF server on the network instead of one Acrobat seat per person. The honest drawback: it is open-core, so some enterprise features (SSO among them) sit in the paid tier, and its text editor is young: it arrived as “Brand new” in version 3.0.
BentoPDF
BentoPDF calls itself “The Privacy First PDF Toolkit” and processes files in the browser, with more than 50 tools listed in its docs. It is free under AGPL-3.0, with a $79 lifetime commercial licence for closed-source use, and had about 16,300 stars on Nov 6, 2026 (repo). It self-hosts as plain static files or from one Docker command. It is best for anyone who will not upload a contract to somebody else's server. The drawback: some processing libraries load from a public CDN at runtime by default, so an air-gapped install needs extra setup.
PDFsam Basic
PDFsam Basic is a desktop application to “split, merge, mix, rotate PDF files and extract pages”, with “No watermarks, no limits.” It is free under AGPL-3.0, runs on Windows, macOS and Linux, and version 6.0.10 shipped on November 4, 2026, with about 4,700 stars (repo). It is best for the person whose only Acrobat job is stitching scans together. The drawback: Basic does not edit text, and the editing editions (PDFsam Enhanced from $69 per user a year, Windows only) are paid and closed source.
Xournal++
Xournal++ is “a handwriting notetaking software with PDF annotation support”, built for writing on top of PDFs with a pen or mouse. It is free under GPL-2.0, version 1.3.8 shipped on September 26, 2026, and it had about 15,600 stars on Nov 6, 2026 (repo). It is best for teachers, students and anyone marking up papers on a tablet. The drawback: on macOS the app is unsigned, and its README explains a workaround to get past Apple's block.
| Tool | Licence | Runs as | Stars (Nov 6, 2026) | Price |
|---|---|---|---|---|
| Stirling PDF | MIT core (open-core) | Desktop, browser, Docker server | ~95,800 | Free self-host; Team $99/mo for 100 users |
| BentoPDF | AGPL-3.0 | In the browser, self-hosted | ~16,300 | Free; $79 commercial licence |
| PDFsam Basic | AGPL-3.0 | Desktop | ~4,700 | Free |
| Xournal++ | GPL-2.0 | Desktop | ~15,600 | Free |
| Adobe Acrobat Pro | Proprietary | Desktop, web, mobile | n/a | $19.99/mo annual, $239.88/yr prepaid |
Stirling PDF vs Adobe Acrobat
Stirling PDF and Adobe Acrobat split along one line: Stirling PDF is a set of tools you run on a file, and Adobe Acrobat is an editor you work inside. For merging, splitting, compressing, converting, OCR and redacting, Stirling PDF does the work for free and can run as one shared server for a whole office. For rewriting a paragraph inside a finished PDF, building complex fillable forms, or sending documents for tracked e-signatures, Acrobat Pro is more polished.
What you actually take on
Adobe Acrobat earns its price in places the toolkits do not reach. Every client, printer and court already accepts what Acrobat produces. Its text editing reflows paragraphs the way a word processor does. Its OCR and form tools are mature, and there is a support line when a 400-page contract will not save at 5pm on a Friday. For a legal or finance team that lives in PDFs all day, $20 a month a person is a fair rent.
A self-hosted Stirling PDF moves that work to you. Somebody keeps the container updated, because a PDF server that accepts uploads is a target. Somebody decides who on the network can reach it. And the desktop tools each do one thing, so a team that needs merge, annotate and sign may end up with two or three apps where Acrobat was one.
- 1Do you mostly merge, split, compress or convert PDFs rather than rewrite them?
- 2Is someone on the team comfortable running a Docker container on the office network?
- 3Does every person who touches a PDF really need their own Acrobat licence?
- 4Do your files contain anything you would rather not upload to a free website?
This series keeps walking a hallway of paid-app doors, from dictation through the login, the CRM, the storefront and the link on the poster, and today's door is the filing room, where every signed contract and scanned receipt ends up. We keep writing these at AppClap because a search for software should put the tool you can own next to the famous one, with the price on the page. Our Adobe Acrobat alternatives page lists everything we track in this category, and if a one-off conversion is all you need, a browser tool like Online2PDF will do it without an account. Or describe the job in your own words: a free PDF editor I can run on my own computer. Thirty seconds on the question is worth it: do you want to rent the editor every year, or keep the toolbox?
