The most popular HTML, CSS, and JavaScript framework for developing responsive, mobile first projects on the web.
174.4k
Stars
78.7k
Forks
267
Open issues
30
Contributors
AI Analysis
Bootstrap is a widely-adopted open-source HTML, CSS, and JavaScript framework designed for building responsive, mobile-first websites and web applications. It serves frontend developers and web designers who need a consistent, pre-built component system and grid layout without writing everything from scratch. It is a general-purpose UI framework broadly applicable across industries, though developers seeking fully custom design systems or utility-first CSS approaches (like Tailwind) may find ...
Inferred from signals mentioned in the README (tests, CI, type safety) — not a review of the actual code.
AI's overall editorial judgment — not an average of the bars above, can weigh other factors too.
Bootstrap at 15: Still the most-installed CSS framework, but growth has slowed to a trickle
Bootstrap is a component-based CSS/JS framework that solves the problem of building consistent, responsive web UIs without writing everything from scratch. It was built primarily for web developers who need reliable, well-documented UI scaffolding fast — from solo developers to enterprise teams. With ~174k GitHub stars, over 5 million weekly npm downloads (historically), and presence across millions of live websites, its real-world adoption is among the most documented of any open-source project. It remains actively maintained, with a push recorded on the current date, though weekly star growth of ~35 reflects a mature, plateau-stage project rather than an expanding one.
Created in 2011 by Twitter engineers Mark Otto and Jacob Thornton to standardize internal tooling, Bootstrap became open source and rapidly dominated frontend development through the 2010s. Bootstrap 5 dropped jQuery dependency and strengthened its utility-class system.
Bootstrap's massive adoption peaked in the 2013–2018 era when it was often the default starting point for any web project. Growth has since flattened as Tailwind CSS, component libraries tied to React/Vue/Angular, and design systems matured. The ~35 stars/week signal reflects a large but no-longer-expanding user base — existing users maintain it, new developers often choose other tooling.
Among the most adoption-documented open source projects in existence. Bootstrap appears on an estimated 20–25% of all websites tracked by crawlers such as BuiltWith and W3Techs as of recent years. npm download counts have historically exceeded 5 million weekly. Used by governments, Fortune 500 companies, educational platforms, and countless CMS themes.
Likely a Sass-based CSS build system producing compiled and minified CSS bundles (grid-only, reboot, utilities, and full), paired with vanilla ES6 JavaScript plugins. RTL support is included. The README shows separate output artifacts for grid, reboot, utilities, and full builds, suggesting a modular compilation pipeline. JavaScript appears to be framework-agnostic with no hard dependencies in v5.
CI badges for JS tests via GitHub Actions and Coveralls coverage tracking are present in the README, indicating automated test coverage is tracked and reported. Specific coverage percentage is not documented in the README excerpt.
Extremely strong. Last push was 2026-06-20 — the current date — indicating daily active maintenance. The project has been continuously maintained for 15 years with a dedicated core team under the twbs GitHub organization. Multi-package-manager support (npm, yarn, Bun, Composer, NuGet) is current and up-to-date.
ADOPT IF: you need a battle-tested, framework-agnostic UI component system with extensive documentation, a massive ecosystem of themes/templates, and a team that doesn't want to assemble a design system from scratch — especially in server-rendered apps, PHP/Ruby/Python backends, or legacy-adjacent environments. AVOID IF: you are building a modern React/Vue/Svelte SPA with a custom design language, or your team is already proficient with Tailwind CSS and utility-first workflows — Bootstrap's component-first approach will feel restrictive and bundle overhead may be unnecessary. MONITOR IF: you are evaluating long-term frontend strategy — Bootstrap 6 has been in discussion and any significant shift in its component model, CSS architecture, or JavaScript approach could change its fit for your stack.
Independent dimensions
Mainstream potential
4/10
Technical importance
7/10
Adoption evidence
10/10
- Mindshare erosion among newer developers, who often learn Tailwind CSS or component frameworks first, may reduce the talent pool comfortable with Bootstrap conventions.
- The opinionated visual defaults (despite theming support) can make achieving fully custom designs more laborious than utility-first or headless approaches.
- Heavy full-bundle CSS size relative to utility-first frameworks that purge unused styles — teams not using build-time tree-shaking may ship more CSS than necessary.
- Slow adoption of modern CSS features (container queries, cascade layers) relative to the pace of the broader ecosystem, though this is improving.
- Ecosystem fragmentation: many Bootstrap 4-era themes and plugins are incompatible with Bootstrap 5, and a future Bootstrap 6 migration would likely repeat this pattern.
Bootstrap will remain in active maintenance and production use on hundreds of millions of websites for at least the next decade, but is unlikely to reclaim the category-default status it held pre-2019. It will stabilize as the preferred choice for non-SPA, backend-centric web development and will continue to serve its installed base reliably.
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Languages
Information
- Website
- https://getbootstrap.com
- Language
- MDX
- License
- MIT
- Last updated
- 6h ago
- Created
- 182mo ago
- Analyzed with
- anthropic/claude-sonnet-4-6
Stars over time
Contributors over time
Top 100 contributors only — repos with more will plateau at 100.
Open issues
Clicking .form-adorn-icon or .form-adorn-text should focus the <input>
var(--bs-font-size-base) is not defined. Setting the 'md' font size has no effect.
Migrate the JavaScript codebase to TypeScript in v6
data-bs-selected-dates does not populate the actual form field.
The .menu-translucent class does not apply to .submenu.
Top contributors
Recent releases
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| Repository | Stars | Week Δ | Language | Score | Updated |
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Tailwind has overtaken Bootstrap in mindshare among greenfield projects since 2021. It uses a utility-first, purge-based approach with no pre-built components, giving more design flexibility but requiring more composition. Bootstrap wins on speed-to-prototype with opinionated components; Tailwind wins on custom design systems.
Bulma is a CSS-only (no JS) framework with a similar component model. It is significantly smaller in adoption and ecosystem, but appeals to developers who want to bring their own JavaScript. Bootstrap's JS plugin system gives it an advantage for teams that want interactivity out of the box.
Foundation was Bootstrap's main rival in the 2010s and is now largely dormant in terms of growth. Bootstrap has substantially more community support, themes, and tooling integrations today.
TW Elements is a Bootstrap-component-inspired layer on top of Tailwind CSS, targeting teams familiar with Bootstrap's component API who have adopted Tailwind. It is a derivative rather than a true replacement, and has far smaller adoption.
These are React-specific component libraries with opinionated design systems (Material Design or headless/Radix). They serve teams already committed to React. Bootstrap remains framework-agnostic, which is an advantage in non-SPA, server-rendered, or multi-stack environments.
