The short answer. Bootstrap Studio is the visual builder for the Bootstrap framework: drag components, get clean markup, which is the fastest path to a responsive page that still reads like HTML. Sparkle is the visual web design app that produces a site rather than a framework project. Espresso is the code editor for people who write the page. CodeKit and Koala are the asset compilers, and MJML is the one for email — semantic markup that compiles to table-based HTML, which is the only way to make an email look the same in a dozen clients. The dividing question is whether the output is a website or an email, because the second is a different medium with a different rendering model and the tools do not overlap.
This guide covers 6 web design apps for macOS. Every fact below is drawn from the same verified records that back each app’s own page. The recommendations are our editorial judgment, not payment.
Quick comparison
| App | What it is | Pricing | Licence | Version |
|---|---|---|---|---|
| Bootstrap Studio | developer utility | not published | not published | 8.0.1 |
| CodeKit | developer utility | not published | not published | 3.37.2 |
| Espresso | developer tool | not published | not published | 25.12 |
| Koala | developer tool | Open source | not published | — |
| MJML | developer tool | Free | not published | — |
| Sparkle | design tool | not published | not published | — |
What actually decides this
- Visual builder or editor. A builder manipulates components and writes markup. An editor writes markup and shows you the result. The first is faster for a page that fits its component model and the second is the only option for anything unusual.
- What the output markup is. Clean semantic HTML can be maintained by hand later. A structure of nested divs with generated classes cannot. If the site will be edited by someone else, this is the deciding property.
- Whether a framework is involved. A Bootstrap builder assumes the grid and the component classes. A general visual tool assumes nothing and generates its own layout system. The two produce sites that are maintained in completely different ways.
- What the compile step is. Sass, Less and CoffeeScript need a compiler, and the compiler needs a watcher. A tool that handles it invisibly is convenient; one that requires a command is fine for a developer and a wall for a designer.
- Whether email is the target. Email HTML is tables, inline styles and a rendering model from 2003. A web design tool produces markup that email clients will mangle. MJML exists because this is a separate problem, not a setting.
Our picks
- Bootstrap Studio — Its record describes creating responsive websites using the Bootstrap framework, which is the builder case. Choose it when you want a visual builder that emits maintainable Bootstrap markup.
- Sparkle — Its record describes professional visual web design, which is the visual case. Choose it when you want to design a site visually and publish it.
- Espresso — Its record describes a web editor for Mac, which is the editor case. Choose it when you write the page yourself.
- CodeKit — Its record describes compiling and auto-refreshing, which is the build case. Choose it when the project needs compilation and live refresh.
- MJML — Its record describes creating responsive emails with semantic syntax and rich components, which is the email case. Choose it when the output is an email.
The apps
Bootstrap Studio
Bootstrap Studio is a developer utility for macOS. A powerful desktop app for creating responsive websites using the Bootstrap framework. Its pricing is not published.
What it does. Powerful Web Development Tool For The Bootstrap Framework.
Bootstrap Studio is listed with current version 8.0.1.
Full profile and verified facts for Bootstrap Studio →
CodeKit
CodeKit is a developer utility for macOS. Web development tool for compiling and auto-refreshing. Its pricing is not published.
What it does. CodeKit is a Mac app that makes it easy to use modern web development tools like npm, Babel, Sass, JavaScript bundling, image optimization, and ESLint.
CodeKit is listed with current version 3.37.2.
Full profile and verified facts for CodeKit →
Espresso
Espresso is a developer tool for macOS. The web editor for Mac is back. For people who make delightful, innovative and fast websites. Its pricing is not published.
What it does. Espresso is the web editor for Mac, more productive than caffeine.
Espresso is listed with current version 25.12.
Full profile and verified facts for Espresso →
Koala
Koala is a developer tool for macOS. GUI application for Less, Sass, Compass and CoffeeScript compilation. It is open source.
What it does. Koala is a gui for Less, Sass, Compass and CoffeeScript. Koala can run in windows, mac, and linux.
Full profile and verified facts for Koala →
MJML
MJML is a developer tool for macOS. Create responsive emails with a semantic syntax and rich components. It is free.
What it does. mjml app: html email editor.
Full profile and verified facts for MJML →
Sparkle
Sparkle is a design tool for macOS. Pro visual web design. Its pricing is not published.
Full profile and verified facts for Sparkle →
How to choose
- Free of charge. MJML — no payment is required.
- No licence fee, source available. Koala — the source can be read and, under the terms of each licence, reused.
- Pricing not published in our data. Bootstrap Studio, CodeKit, Espresso and Sparkle — check the developer’s own site before assuming anything about cost.
Open source: Koala (1 of 6).
Common mistakes
- Designing an email in a web design tool and testing it in one client.
- Choosing a visual builder and then hand-editing its generated markup.
- Assuming a framework builder produces markup a designer can maintain.
- Forgetting that a compile step is a build dependency, not a preference.
How this guide was put together
Each app’s facts come from its own record: the developer’s own pages and repository, the App Store listing where one exists, and the documentation, each with a source grade and an access date. Where a fact rests on the developer’s own statement rather than on something we verified independently, the sentence says so. Where our data has no value for something, the guide says “not published” instead of guessing.
A price appears here only where the record carries one from a stated source; the guide never estimates one, and it records the pricing model alongside so the two can be read together. Prices change and vary by region, so each app links to its own page for the current detail.
The facts and the recommendations are kept apart on purpose. Everything in the app entries, the comparison table and the answers above is composed from the records. The short answer, the criteria and the picks are our editorial judgment: they reflect what we would choose and why, and they are not paid for. Where we make a recommendation we name the condition it applies under, because we do not call anything “the best” without explaining the criteria.
Frequently Asked Questions
How do I choose between these web design apps?
There is no single answer — it depends on what you need. This guide covers 6 web design apps: Bootstrap Studio, CodeKit, Espresso, Koala, MJML and Sparkle. They differ mainly in pricing model, licence and the trade-offs each one carries. Pick by the trade-off you care about rather than by rank.
Are these web design apps free?
Pricing across this group: not published (Bootstrap Studio, CodeKit, Espresso and Sparkle), open source (Koala) and free (MJML). Where we list pricing as not published, the developer does not state a model we could verify — check their own site before assuming anything about cost. We quote a price only where the record carries one from a stated source, and we never estimate one. Prices change and vary by region and by store, so always check the developer’s own page for the current figure.
Which of these web design apps are open source?
Koala (not published) is open source.
Do these web design apps support Apple Silicon?
Our data does not carry an explicit Apple Silicon statement for any app in this group, so we do not claim one. The absence of a statement is not the same as the absence of support.
How do I choose between them?
Start with how you pay: the guide groups these apps by pricing model, because the budget is the constraint most people actually have. Then check the trade-offs listed for each app: the limitations are the part that decides most people’s choice, because they describe what the app will not do for you.
