87.3% of Websites Using Bootstrap Run a Version That No Longer Gets Updates

    87.3% of websites that show their Bootstrap version run Bootstrap 4 or older, versions that no longer receive fixes. Bootstrap 3, unsupported since July 2019, is still the most common version, on 1,001,551 homepages.

    Websites that show their Bootstrap version by bootstrap version
    Bootstrap 5 (supported)
    12.7%
    Bootstrap 4 (unsupported since January 2023)
    39.5%
    Bootstrap 3 (unsupported since July 2019)
    45.9%
    Bootstrap 2 or older
    1.9%

    Source: Suff Digital analysis of 2,184,137 homepages with a readable Bootstrap version · the public HTTP Archive crawl of 15.5 million websites, September 2026

    Websites running unsupported Bootstrap by website popularity
    Top 10,000
    86.8%
    10k to 100k
    84.5%
    100k to 1 million
    83.8%
    1 million to 10 million
    87.5%
    Beyond the top 10 million
    87.5%
    All websites
    87.3%

    Source: Suff Digital analysis of 2,184,137 homepages with a readable Bootstrap version · the public HTTP Archive crawl of 15.5 million websites, September 2026

    Source: 87.3% of Websites Using Bootstrap Run a Version That No Longer Gets Updates - Suff Digital