# Error: A valid license key is required to use the view only build of PDF.js Express

**URL:** <https://pdfjs.community/t/error-a-valid-license-key-is-required-to-use-the-view-only-build-of-pdf-js-express/3145>\
**Category:** Technical Support\
**Tags:** pdfjs-express\
**Created:** [February 20, 2024, 2:56pm UTC](https://pdfjs.community/t/error-a-valid-license-key-is-required-to-use-the-view-only-build-of-pdf-js-express/3145 "2024-02-20T14:56:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![david.dekker](https://avatars.discourse-cdn.com/v4/letter/d/ac8455/32.png) [@david.dekker](https://pdfjs.community/u/david.dekker)\
**Post date:** [February 20, 2024, 2:56pm UTC](https://pdfjs.community/t/error-a-valid-license-key-is-required-to-use-the-view-only-build-of-pdf-js-express/3145/1 "2024-02-20T14:56:45Z")

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**Which product are you using?**  
PDF.js Express Viewer

**PDF.js Express Version**  
‘8.7.4’

**Detailed description of issue**  
Im trying Webviewer out on localhost but get the error:  
`PDFJS.express: A valid license key is required to use the view only build of PDF.js Express. Get your free license key at https://pdfjs.express/profile (account required)`

Even though i set the free license key which i generated in my profile.

**Code snippet**  
PDFJSExpress(  
{  
path: path,  
licenseKey: ‘my-license-key’,  
initialDoc: ‘/Re\_sabel.pdf’,  
},  
this.$refs.viewer  
).then((instance) =\> {

---

<div class="post-metadata">

**Author:** ![tgordon](https://avatars.discourse-cdn.com/v4/letter/t/aca169/32.png) [@tgordon](https://pdfjs.community/u/tgordon)\
**Post date:** [February 20, 2024, 7:29pm UTC](https://pdfjs.community/t/error-a-valid-license-key-is-required-to-use-the-view-only-build-of-pdf-js-express/3145/3 "2024-02-20T19:29:15Z")

</div>

Hello david.dekker,

The license key should not be in the format ‘my-license-key’, could this be a variable instead?

Best regards,  
Tyler

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<div class="post-metadata">

**Author:** ![david.dekker](https://avatars.discourse-cdn.com/v4/letter/d/ac8455/32.png) [@david.dekker](https://pdfjs.community/u/david.dekker)\
**Post date:** [February 21, 2024, 9:58am UTC](https://pdfjs.community/t/error-a-valid-license-key-is-required-to-use-the-view-only-build-of-pdf-js-express/3145/4 "2024-02-21T09:58:30Z")

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In my code the actual key is in there.  
Took it out for the example.

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<div class="post-metadata">

**Author:** ![darren](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@darren](https://pdfjs.community/u/darren)\
**Post date:** [May 28, 2024, 1:21pm UTC](https://pdfjs.community/t/error-a-valid-license-key-is-required-to-use-the-view-only-build-of-pdf-js-express/3145/5 "2024-05-28T13:21:44Z")

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Did you resolve this @david.dekker ? I’m having the same issue.