CSS Flexbox in Bootstrap: Best Practices

Curtis Chau

Updated:July 5, 2026

Are Bootstrap / Flex / CSS supported?

Chrome

Yes, as of IronPDF release version 2021.9.3678, which features our brand new pixel-perfect Chrome rendering engine.

NuGet: IronPDF
API: IronPDF API

WebKit (legacy, pre-2021.9)

Note: The legacy WebKit renderer is no longer available in current versions of IronPDF. Since 2021.9 the Chrome engine is the only renderer, and it fully supports Flexbox, Bootstrap, and CSS3 — so the WebKit limitations and table-based workarounds below no longer apply. This section is retained for historical reference only.

Using the older WebKit engine, IronPDF supported HTML 5, Bootstrap 3, and CSS3.

CSS columns and Flex were not fully supported in WebKit, so alternative structures, including tables, were recommended.

CSS classes that emulated Flexbox for simple use cases were table, table-row, table-cell.

Curtis Chau

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Technical Writer

Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.

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