explaingit

onevcat/kingfisher

★ 24,329SwiftAudience · developerComplexity · 2/5ActiveLicenseSetup · easy

TLDR

Swift library that downloads images from the internet, caches them locally, and displays them in iOS and macOS apps without freezing the UI.

Mindmap

mindmap
  root((Kingfisher))
    What it does
      Download images async
      Cache in memory and disk
      Resize and process images
      Fade-in animations
    Key features
      Low Data Mode support
      Configurable expiration
      Size limit controls
      Round corner effects
    Use cases
      Profile picture display
      Product photo galleries
      Remote image loading
      Offline image access
    Tech stack
      Swift language
      UIKit support
      SwiftUI support
    Audience
      iOS developers
      macOS developers

Things people build with this

USE CASE 1

Display user profile pictures in a social media app without blocking the UI while they download.

USE CASE 2

Build a product catalog that loads thumbnail images from a server and caches them for offline browsing.

USE CASE 3

Add fade-in animations to images as they load, improving the visual polish of your app.

USE CASE 4

Serve lower-resolution images automatically when users have limited data connections.

Tech stack

SwiftUIKitSwiftUI

Getting it running

Difficulty · easy Time to first run · 5min
Use freely for any purpose, including commercial use, as long as you keep the copyright notice.

In plain English

Kingfisher is a Swift library for iOS and macOS apps that handles loading images from the internet. The problem it solves is a common one in mobile development: you have an app that needs to display user profile pictures, product photos, or any other images hosted on a remote server. Doing this correctly, without freezing the app while the image downloads, while also not re-downloading the same image every time, requires a fair amount of plumbing. Kingfisher handles all of that for you. It downloads images asynchronously in the background so the user interface never locks up. Once an image is downloaded, it is stored in two places: memory (for fast, instant access while the app is open) and disk (so the image is available even after the app is closed and reopened). This caching system is fully configurable, you can set expiration times and size limits. Beyond basic downloading and caching, Kingfisher includes image processing tools that let you resize images to fit a display, apply round corners, and add fade-in animations when images appear. It also supports Apple's Low Data Mode, letting you serve lower-resolution images when a user's connection is limited. An iOS or macOS developer would add Kingfisher to their app any time they need to display images from a URL. It works with both UIKit (the traditional Apple UI framework) and SwiftUI (the newer declarative framework), and is written entirely in Swift.

Copy-paste prompts

Prompt 1
Show me how to load an image from a URL into a UIImageView using Kingfisher and cache it automatically.
Prompt 2
How do I use Kingfisher in SwiftUI to display images with a fade-in animation?
Prompt 3
Set up Kingfisher to resize downloaded images to fit a specific screen size and add rounded corners.
Prompt 4
Configure Kingfisher's cache to expire images after 7 days and limit total cache size to 100MB.
Prompt 5
How do I make Kingfisher serve lower-resolution images when the user has Low Data Mode enabled?
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Generated 2026-05-18 · Model: sonnet-4-6 · Verify against the repo before relying on details.