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Stirling PDF’s 3.0 release adds folder-based and server-side automation to a free, open-source PDF toolkit that includes editing, redaction, OCR and file comparison. A hands-on XDA Developers account says local mode keeps supported tools on the user’s computer, while some features require Stirling’s cloud or a self-hosted setup.

Stirling PDF 3.0 adds batch-processing and automation features to a free, open-source toolkit that can handle tasks such as editing, redacting and comparing PDF files. In an Oct. 23 hands-on report, XDA Developers described using the software as an alternative to some paid Adobe Acrobat features, while noting that the privacy and feature trade-offs depend on whether users choose local, cloud or self-hosted processing.

The review says Stirling’s documentation lists more than 55 tools, including form filling, signing, merging, compression, OCR and document security. Its editor, rebuilt for version 3.0, moved out of alpha, allowing users to click existing text and edit it. The reviewer found a limitation: if the document’s embedded font does not include a character being added, Stirling substitutes Helvetica, which may look different from the surrounding text.

Other tools highlighted include redaction, which can search for instances of a word to black out or let users draw boxes over content, and Compare, which marks text differences between two PDFs. The Sanitize tool removes JavaScript and embedded files, according to the review. These functions overlap with features the article says require Acrobat Pro, while Acrobat’s free online merge and compression tools require uploading files. The review gives Acrobat Pro’s price as $20 a month and says editing existing text in Acrobat requires at least a Standard plan, listed at $15 monthly on an annual plan.

Version 3.0’s PDF Processor can run saved tool sequences on batches of PDFs from folders or FTP or S3 storage and monitor for new files. The full Processor dashboard is available in Stirling’s browser version; the desktop app instead offers a folder-processing option that watches a selected folder while the app is open. Stirling also has an agent that can answer questions about an open PDF or run tools. Users can connect it to a local model, an API or Stirling’s AI service, which the source says uses Claude and VoyageAI and includes 1,000 monthly credits.

Keeping Sensitive PDF Work Local

The appeal described in the review is not just avoiding a subscription. Identity documents and bank statements can contain information users may not want to upload to an online service. Stirling offers a local mode in which supported tools run on the user’s computer, according to the article, giving users a way to do some PDF work without sending files to Adobe or Stirling’s servers.

That choice has limits. Stirling marks some cloud-dependent features with a cloud icon; the review says those features are blocked in Local Only mode, including OCR and Office-file conversion. Users who want more capabilities while keeping processing under their own control can self-host Stirling with Docker, but that requires setup. The software therefore offers a different balance of cost, convenience and data handling rather than a universal replacement for Acrobat.

For people who routinely need to edit PDFs, redact information or process batches, the tool may reduce reliance on a paid Acrobat plan. The review’s comparison is based on one person’s hands-on use, not a controlled test of every feature or a guarantee that all workflows will work equally well.

What Changed in Version 3.0

Stirling already had an Automate tool before version 3.0, according to the source. It lets users save a sequence of tools and apply it to a file; one example preset removes risky content and then runs OCR. The update extended that idea with the PDF Processor, intended to handle large batches and monitor storage locations for incoming files.

The source distinguishes among three ways to use the software: desktop local mode, Stirling’s cloud-connected services, and self-hosting with Docker. The reviewer says signing out and using Local Only keeps supported processing on the computer, while self-hosting restores OCR and allows AI connections to local models through Ollama or other OpenAI-compatible servers. The review describes self-hosting as the way to use version 3.0 automation without involving Stirling’s cloud.

““Every tool then runs on your computer and nothing gets uploaded anywhere.””

— XDA Developers reviewer

Limits and Privacy Trade-Offs

The source is a single hands-on review, and it does not provide independent testing of Stirling’s performance, reliability or security. It also does not establish that every tool behaves identically across operating systems or document types. Users should check which functions operate locally and which involve a service before processing sensitive files.

The review reports that Stirling’s AI service uses Claude and VoyageAI and provides 1,000 credits per month, but it does not spell out how quickly different tasks consume credits, the service’s data-retention practices, or the terms attached to the models. The author also says file classification appeared to run in the background and tagged documents as HR; the reason was not confirmed, with the reviewer suggesting onboarding may have enabled it. The article does not establish whether that behavior is typical or how users can manage it in every setup.

Choosing a Setup for Each File

Readers considering Stirling can start by identifying which tasks they need and whether those tasks are supported in local mode. For files that must remain on a personal computer, the review describes signing out to use local processing, with unsupported cloud-only features blocked. Users seeking OCR, local-model AI connections or cloud-independent automation can investigate self-hosting with Docker, while accounting for the additional configuration it requires.

The source does not announce a future release date or a change to Stirling’s pricing. For now, the practical next step is to test the relevant tools on non-sensitive documents, confirm where processing takes place, and review settings such as classification before directing a folder of private files to an automated workflow.

Key Questions

Can Stirling PDF replace Adobe Acrobat?

It can cover some tasks the XDA review compares with paid Acrobat features, including editing existing text, redaction, comparison and OCR. The review does not establish that it replaces every Acrobat feature or suits every professional workflow.

Does Stirling PDF upload files in local mode?

The review says supported tools in Local Only mode run on the computer. Some cloud-dependent features, including OCR and Office-file conversion, are blocked rather than processed locally in that mode.

What did Stirling PDF 3.0 add?

The release added the PDF Processor, which can apply saved tool sequences to batches and monitor folders or supported storage locations for new PDFs. It also rebuilt the editor, which the review says moved out of alpha.

How can users run OCR without Stirling’s cloud?

According to the review, users can self-host Stirling with Docker. It says this setup restores OCR and can connect AI features to local models, though it requires additional configuration.

Is Stirling PDF’s AI fully local by default?

No. The review describes several options: a local model, an API, or Stirling’s own AI service. Users who want local AI processing need to connect a local model through a supported self-hosted setup.

Source: XDA Developers