# Security! Does PDF.js Express allow to disable browser cache for PDF form values populated by User?

**URL:** <https://pdfjs.community/t/security-does-pdf-js-express-allow-to-disable-browser-cache-for-pdf-form-values-populated-by-user/1373>\
**Category:** Technical Support\
**Created:** [February 11, 2022, 11:31am UTC](https://pdfjs.community/t/security-does-pdf-js-express-allow-to-disable-browser-cache-for-pdf-form-values-populated-by-user/1373 "2022-02-11T11:31:54Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![evgeniy.zhygliy](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@evgeniy.zhygliy](https://pdfjs.community/u/evgeniy.zhygliy)\
**Post date:** [February 11, 2022, 11:31am UTC](https://pdfjs.community/t/security-does-pdf-js-express-allow-to-disable-browser-cache-for-pdf-form-values-populated-by-user/1373/1 "2022-02-11T11:31:54Z")

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**Which product are you using?**

**PDF.js Express Version**

**Detailed description of issue**  
{My project is related to Healthcare organizations in the US and requires the highest security attention. Users will be populating PDF forms with personal and sensitive data which should be totally secured.  
Before start using our service, I need to know the answers to the following questions?

1. Does the browser cache PDF-form’s values in your PDF viewer realization?
2. Does your service itself have its own layers of cache that is related to the PDF form’s values?
3. If there is at least one answer for the first two ones like YES, is it possible to disable caching and guarantee that no user-inputted data will not be stored in the Browser?}

**Expected behaviour**  
{PDF form’s values should not be cached by browser}

**Does your issue happen with every document, or just one?**  
{}

**Link to document**  
{Provide a link to the document in question if possible}

**Code snippet**  
{Provide a relevant code snippet}

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<div class="post-metadata">

**Author:** ![system](https://canada1.discourse-cdn.com/flex031/uploads/pdfjscommunity/original/1X/ffbcd25c7d423db8d5acd5db201c272f4db306dd.png) [@system](https://pdfjs.community/u/system)\
**Post date:** [February 11, 2022, 11:31am UTC](https://pdfjs.community/t/security-does-pdf-js-express-allow-to-disable-browser-cache-for-pdf-form-values-populated-by-user/1373/3 "2022-02-11T11:31:59Z")

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**Hello, I’m Ron, an automated tech support bot 🤖**

While you wait for one of our customer support representatives to get back to you, please check out some of these documentation pages:

Guides:
- [Set up real-time collaboration](https://pdfjs.express/documentation/collaboration/setup)
- [Support forms with PDF.js Express](https://pdfjs.express/documentation/forms/overview)
- [Best practices for PDF.js Express - Load documents with loadDocument](https://pdfjs.express/documentation/learn-more/best-practices#load-documents-with-loaddocument)

APIs:
- [PDF.js Express Utilities](https://pdfjs.express/api/utils/index.html#__anchor)
- [Core.PartRetrievers](https://pdfjs.express/api/Core.PartRetrievers.html#__anchor)
- [Core - getDefaultBackendType()](https://pdfjs.express/api/Core.html#.getDefaultBackendType__anchor)

Forums:
- [Access to PDF.js viewer when your servers are unavailable](https://pdfjs.community/t/access-to-pdf-js-viewer-when-your-servers-are-unavailable/1260/1)
- [How to make sure requests are correctly cache busted](https://pdfjs.community/t/how-to-make-sure-requests-are-correctly-cache-busted/284/1)
- [Download Button is not working](https://pdfjs.community/t/download-button-is-not-working/1366/1)

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<div class="post-metadata">

**Author:** ![Logan](https://yyz1.discourse-cdn.com/flex031/user_avatar/pdfjs.community/logan/32/13_2.png) [@Logan](https://pdfjs.community/u/Logan)\
**Post date:** [February 16, 2022, 3:43pm UTC](https://pdfjs.community/t/security-does-pdf-js-express-allow-to-disable-browser-cache-for-pdf-form-values-populated-by-user/1373/4 "2022-02-16T15:43:19Z")

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Hi there,

We do not do any form caching on our end - any caching you may be seeing would be a result of browser caching which we do not control.

Thanks!  
Logan