Privacy policy

Most StackPDF tools run in your browser. When you open a file in one of them, the file is read and processed on your device, inside the browser tab. It is not sent to us, and we can’t see it.

The result downloads to your device, or stays in My files in this browser if you keep it there. Each tool page says “Runs in this browser” when this applies.

A few tools need a server: Convert PDF to PDF/A, PDF to Word, PDF to Excel, PDF to PowerPoint, PDF to CSV, Word to PDF, Excel to PDF, PowerPoint to PDF, HTML to PDF and OCR PDF. They are part of Premium. Before anything is uploaded, the tool tells you and asks you to confirm.

• Your file goes straight to private storage over an encrypted connection, through a link that expires after 15 minutes.
• Office files are converted with LibreOffice on servers that have no internet access. OCR uses Amazon Textract.
• HTML to PDF loads the web address you give it. It refuses private and internal addresses.
• The file and the result are deleted when you have the result. Anything left over is deleted automatically within a day.
• Our logs never include the contents of your files.

My files keeps the documents you choose to save. They are stored in this browser’s storage on your device, and you can delete them at any time. Deleted files stay in Recently deleted for 30 days, then they are removed.

With Premium, My files is also kept in your cloud library, so it syncs to your other devices. The library holds up to 1,000 MB. Files are stored privately and encrypted, they are never shared through public links, and download links expire after 15 minutes. Earlier versions of a file are kept for 30 days so a mistake can be undone.

If Premium ends, your cloud library turns read-only. You can still download your files for 90 days, then they are deleted. Files saved in this browser are not affected.

You don’t need an account for the free tools. You need one for Premium on the web. You sign in with Google, Apple or a link sent to your email, through Firebase Authentication. There are no passwords.

When you have an account, we keep:

• Your email address, and your name if your sign-in provider shares it
• Your plan, renewal date and subscription status
• How much storage you use
• Counts of the cloud jobs you run, to apply the fair-use limits
• Signatures and details you choose to save for filling in forms

Payments are handled by Stripe on the web, and by the App Store or Google Play in the apps. We don’t receive your full card number.

The website uses Google reCAPTCHA Enterprise to check that protected requests come from a real browser running StackPDF. It looks at signals from your browser and device, and Google may set its own cookies. These service-security checks are separate from optional product analytics.

We may block accounts that abuse the service, such as by sharing or scripting a paid account.

We use PostHog to understand how people find StackPDF, navigate its pages and use its tools, so we can improve the service. We measure known buttons and controls, tool types, broad file-size and performance categories, and successful or failed operations. Search activity records length and result counts, never the words you search for.

Analytics never includes document contents, file or folder names, typed form contents, signatures, passwords, email addresses, payment details or private URL parameters. Session recording, replay, advertising tracking and automatic DOM-content capture are disabled. We do not send Firebase account IDs to PostHog.

• United States: we use pseudonymous event analytics, subject to your privacy choice and browser signals. A random browser identifier and approved source categories let us understand visits and product journeys. We store this identifier and sanitized acquisition information in first-party browser storage. Events can include your plan and whether you are signed in, without your name or account identifier. PostHog processes these events in its U.S.-hosted service.
• United Kingdom, Australia, New Zealand, Canada, Singapore and Japan: we send anonymous aggregate counts through StackPDF’s relay. These counters have no persistent visitor, account or session identifier, and they are not used to reconstruct individual journeys. Optional analytics uses no cookies or persistent browser storage in this mode. The relay does not retain visitor IP addresses or user-agent strings in analytics records.
• Other countries or an unknown region: optional analytics stays off. If a regional check cannot be completed, it also stays off.

The region comes from the country provided by our hosting network. In aggregate mode, only approved event, route, tool, source and control categories are counted. Raw referral URLs, campaign text and query strings are discarded. Aggregate counts are processed in our U.S. infrastructure and PostHog project.

You can disable optional analytics below or in Account → Settings. We also keep it off when your browser sends Global Privacy Control or Do Not Track. Restoring analytics uses the reviewed level for your region and never enables individual tracking in an aggregate-only or off region. Your tools, files and subscription work the same either way.

Disabling stops future optional collection and removes the optional analytics identifier and source information from this browser. It does not automatically erase events already received. For questions about analytics retention or requests concerning your data, email support@stackpdf.com.

StackPDF doesn’t use advertising cookies, and we don’t sell or share your data for advertising. The website uses browser storage for the service and, in regions with pseudonymous product analytics enabled, for the optional information described above:

• Your settings, your sign-in and your plan, in the browser’s local storage
• Files you keep in My files, in the browser’s IndexedDB storage
• Security cookies that Google may set for reCAPTCHA Enterprise
• A random analytics identifier and sanitized source categories, only when regional pseudonymous analytics is enabled
• Your analytics privacy choice, so this browser can remember it

Use the analytics controls to change optional analytics. You can also clear storage in your browser’s settings. Clearing all site storage signs you out and removes files saved only in this browser; it also removes this browser’s saved analytics choice. A signed-in account’s saved choice is checked again when you sign in.

• Amazon Web Services: hosting, storage, cloud tools and OCR (Amazon Textract)
• Google Firebase: sign-in and security checks, plus crash reports and analytics in the mobile apps
• RevenueCat: subscription status
• Stripe, Apple and Google: payments
• PostHog: regional product analytics, hosted in the United States

• Download or delete any file in My files at any time.
• Delete your account in Account, then Settings. This deletes your account, your cloud library and its folders, and your usage records. Files saved in this browser stay on this device.
• If you pay through the App Store or Google Play, cancel the subscription there as well.
• Disable optional analytics in the controls above or in Account → Settings. Browser privacy signals also keep it off.
• For a copy of your data or any other request, email support@stackpdf.com.

When this policy changes, we update this page and the date at the top.

Questions: support@stackpdf.com. The terms cover how you may use StackPDF.