21st Design Bug Bot

Review pull requests for UI design issues and suggested fixes

Tool type: AI interface review GitHub application
Made for: Teams reviewing React interface changes
Runs on: GitHub pull requests and web review dashboard
Last checked: 30 Oct 2026; 1 product sources

What it does

21st Design Bug Bot is a GitHub application that reviews interface changes in React projects. It checks design-system consistency, typography, responsive behavior, interaction, motion, performance and copy. Reviews include findings, severity and suggested code changes, with comparison screenshots when the project can be rendered successfully.

Install the application on selected repositories and choose when reviews should run. It can comment, create checks and push a branch for a proposed fix, but does not merge or block pull requests. The first five successful reviews are free; later reviews use the same AI credit balance as 21st AI. A repository pauses at its monthly credit cap with a neutral check. Treat the score and proposed patches as review assistance and inspect the result before merging.

What it can do

Pull-request design review
Responsive-layout checks
Design-token checks
Typography checks
Suggested fix code
Conditional screenshots
Review scores

Works with

GitHub
React
Next.js
Vite
Tailwind CSS

Before you choose

Screenshots depend on successful rendering of the project.
The app can push a fix branch; repository permissions should match the intended use.
The five-review allowance is one-time, with no expiry.

Listed under

Get started

Sign in and install the 21st GitHub App on selected repositories.
Choose review triggers and run it on a pull request.
Review the findings and proposed patch before merging any change.

Connect Design Bug Bot to GitHub

Plans and prices

Prices in USD

After five successful reviews, use a Builder + AI subscription from $15/month equivalent billed annually. Reviews consume shared AI credits; each repository caps usage at 2,000 credits per month.

Builder + AI entry plan$15/moMonthly equivalent billed annually; review usage consumes shared credits.

Source: 21st.dev/design-bug-bot, checked 30 Oct 2026. Prices can change; check before you buy.

Sources for this overview

Product pages, documentation, and pricing checked 30 Oct 2026. Each source supports part of the overview; availability and prices can change.

Design Bug Bot - design review on every pull request | 21st ↗21st.dev

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What’s changed

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Signals

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Data and security

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Training on your files, compliance, hosting and the models behind it. Free with an account.

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Where this comes from

How we research

Company website: 21st.dev: product, pricing and policy pages
YC directory mirror: Batch and company name
Social accounts: Accounts the company links, and its posts on X
Human review: Checked by a person
knowledge_base
manual_review

Last checked 30 Oct 2026. Every field keeps its source and date; unknown means we couldn’t confirm it.