FSCalendar vs SDWebImage
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A customizable calendar view control for iOS apps, usable from Objective-C or Swift.
Open source · MIT
Loads, caches and displays web images on Apple platforms, with a UIImageView-style API.
The short answer
Choose FSCalendar if you need…
- iOS developers who need a calendar or date-picker view in their app
- Teams with existing Objective-C code that also want Swift support
- Developers who want to customize the calendar's look and cell content
- Developers who use Interface Builder and want the calendar set up visually
Choose SDWebImage if you need…
- iOS or macOS app developers who need to show remote images in lists or grids
- Teams that want caching, progressive loading and image transformations handled by a tested library
- Developers building SwiftUI apps who want to use the separate SDWebImageSwiftUI module built on this core
Side-by-side
| FSCalendar | SDWebImage | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 10.6k | 25.6k |
| Setup difficulty | Intermediate | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | Objective-C | Objective-C |
| Last code update | 2 years ago | 7 months ago |
What each one is
FSCalendar
FSCalendar is a library that lets iOS app developers add a calendar widget to their apps. It can be styled and customized, and it works with both Objective-C and Swift projects. Developers use it when they want users to view or pick dates inside an app instead of building a calendar from scratch.
SDWebImage
SDWebImage is an Objective-C library for Apple platforms that downloads images from URLs asynchronously and keeps them in memory and on disk so they do not need to be fetched again. It adds helper methods to UI elements such as UIImageView, UIButton and MKAnnotationView so app developers can show a web image with a single call. It also supports animated images like GIF and APNG, and can be extended with plugins for other formats.
Best for
FSCalendar
- iOS developers who need a calendar or date-picker view in their app
- Teams with existing Objective-C code that also want Swift support
- Developers who want to customize the calendar's look and cell content
- Developers who use Interface Builder and want the calendar set up visually
SDWebImage
- iOS or macOS app developers who need to show remote images in lists or grids
- Teams that want caching, progressive loading and image transformations handled by a tested library
- Developers building SwiftUI apps who want to use the separate SDWebImageSwiftUI module built on this core
Strengths
FSCalendar
- Widely used according to the README badges (over 10,000 apps and over 500,000 downloads, as stated there)
- Supports several install routes: CocoaPods, Carthage, Swift Package Manager, and manual file copy
- Includes example projects in both Swift and Objective-C to learn from
SDWebImage
- Widely used, with about 25,600 GitHub stars and an active push date in April 2026
- Covers downloading, memory and disk caching, and background decoding in one package
- Modular design with separate plugins for extra formats and SwiftUI
Not ideal for
FSCalendar
- Non-developers, since this is a code library rather than an app (it has no end-user interface of its own)
- Android or web projects, since the README only describes iOS usage
- Projects that need the calendar to resize itself automatically without extra code, because the README says the calendar does not update its frame by itself and the app must handle height changes
SDWebImage
- Developers working only with Android, web browsers or other non-Apple platforms, since the library targets Apple platforms
- Beginners with no Xcode or Apple-platform experience, since integration assumes familiarity with app development
- Projects needing modern animated formats such as animated WebP or HEIC by default, since the README says these must be registered manually
Trade-offs
FSCalendar
- The README says the calendar does not resize itself; the developer must update its height in a delegate method
- The latest release listed is 2.8.3 and the README mentions a newer SPM version (2.8.4), so version details should be checked directly
- Some README build and CI badges link to Travis CI, which may not reflect current testing status
SDWebImage
- Only for Apple platforms; the README does not cover other ecosystems
- Many advanced features are documented in an external wiki, so the README alone gives limited detail
- Some formats such as animated WebP need manual registration, and visionOS support is described as beta for some versions
Getting started
FSCalendar
Add to a CocoaPods Podfile
pod 'FSCalendar'Add as a Swift Package dependency
.package(url: "https://github.com/WenchaoD/FSCalendar.git", from: "2.8.4")SDWebImage
Clone the repository
git clone https://github.com/SDWebImage/SDWebImageFrequently asked questions
What is the difference between FSCalendar and SDWebImage?
FSCalendar: A customizable calendar view control for iOS apps, usable from Objective-C or Swift. SDWebImage: Loads, caches and displays web images on Apple platforms, with a UIImageView-style API. FSCalendar suits ios developers who need a calendar or date-picker view in their app, while SDWebImage suits ios or macos app developers who need to show remote images in lists or grids.
Are FSCalendar and SDWebImage free?
FSCalendar: Free and open source. SDWebImage: Free and open source.
Is FSCalendar or SDWebImage more popular?
SDWebImage has more GitHub stars (25.6k) than FSCalendar (10.6k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to FSCalendar and SDWebImage?
Other options people compare them with include SVProgressHUD, SwifterSwift, Eureka, SwiftyJSON, NVActivityIndicatorView.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.