# File Island
Drop images, videos, audio, or a whole folder at the top of your Mac and convert locally.
File Island stays quietly near the notch until you need it. No media upload and no separate FFmpeg installation.
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Format matrix
## See it in 11 seconds
[](https://treafree.github.io/FileIsland/#mixed-folder)
> Click the poster to play in your browser. One folder containing images, video, and audio can be configured by media type and converted as a single batch.
## Why File Island
Full commercial conversion suites can be capable but may use one-time or subscription pricing. Browser converters are convenient but usually require an upload. FFmpeg is exceptionally flexible, but not everyone wants to memorize commands. File Island offers a native Mac alternative: a quiet Finder-first interface for common local media work, with safe batching and an automation API when you need it.
| Workflow | File Island | Browser converters | Single-purpose GUI apps | FFmpeg CLI |
| --- | --- | --- | --- | --- |
| Images, video, and audio in one place | ✅ | Varies | Usually one media family | ✅ |
| Mixed-folder batch processing | ✅ | Usually upload-limited | Varies | Requires commands/scripts |
| Media stays on the Mac | ✅ | Usually uploaded | ✅ | ✅ |
| Finder drag-and-drop controls | ✅ | ✅ | ✅ | — |
| Structured CLI / agent use | ✅ | — | Uncommon | ✅ |
| Extra runtime setup | None; included in DMG | Browser | Varies | Install and maintain separately |
File Island does not try to replace a professional editor or claim formats and sharing rules that have not been verified. It fails closed and preserves sources when a request cannot be completed safely.
## Highlights
- native SwiftUI + AppKit interface for notched and non-notched Macs;
- single files, multiple selections, and ordinary-folder drops;
- type-aware image, video, and audio groups with independent controls;
- heterogeneous folder batches with relative folder structure preserved;
- JPEG/PNG image output with dimensions, quality, target size, and metadata controls;
- high-compatibility H.264/AAC MP4 video output with Source, 1080p, 720p, and target-size choices;
- M4A, WAV, FLAC, and AIFF audio output;
- fast size- and/or duration-constrained splitting for eligible H.264 MP4/MOV files without re-encoding the streams;
- one-time output-folder authorization, collision-safe names, optional single-output Clipboard copy, and no source overwrite;
- local-only processing with no account, ads, analytics SDK, or media upload;
- bundled universal FFmpeg/ffprobe and an isolated media validator—Homebrew is not required;
- English, Simplified Chinese, and System language modes;
- a shared conversion core for the app and structured `fileisland` CLI.
See the [format matrix](docs/FORMAT_MATRIX.md) for the exact verified input and output scope.
## Download, install, and use
Install with Homebrew:
```sh
brew install --cask treafree/tap/file-island
```
Or install the DMG manually:
1. Download the DMG and matching SHA-256 from [GitHub Releases](https://github.com/TREAFREE/FileIsland/releases/latest).
2. Verify the checksum, open the DMG, and drag **File Island.app** to **Applications**.
Then launch File Island from Applications, drag media or a folder from Finder to the Island at the top of the screen, configure each media group, and choose **Start**. Authorize a persistent output folder on first use; later conversions reuse that folder automatically.
The current early-access build is not signed with Apple Developer ID and is not notarized. macOS may block its first launch. Try to open it once, then use **System Settings → Privacy & Security → Open Anyway** only for a checksum-verified DMG from this repository's official Release. Never disable Gatekeeper.
The Homebrew cask installs the same unsigned release artifact, so the same first-launch warning may apply. Future releases require a version and checksum update in the [`TREAFREE/homebrew-tap`](https://github.com/TREAFREE/homebrew-tap) repository before `brew upgrade --cask file-island` can install them.
For illustrated, step-by-step videos, read the [complete user guide](docs/USER_GUIDE.md).
## Demos
| Image conversion | Video conversion and splitting |
| --- | --- |
| [](https://treafree.github.io/FileIsland/#image) | [](https://treafree.github.io/FileIsland/#video) |
| [▶ Play image demo](https://treafree.github.io/FileIsland/#image) | [▶ Play video demo](https://treafree.github.io/FileIsland/#video) |
| Audio conversion | Settings and language |
| --- | --- |
| [](https://treafree.github.io/FileIsland/#audio) | [](https://treafree.github.io/FileIsland/#settings) |
| [▶ Play audio demo](https://treafree.github.io/FileIsland/#audio) | [▶ Play settings demo](https://treafree.github.io/FileIsland/#settings) |
## Current limitations
- macOS 15 or newer is required;
- MP3 is accepted as input but is not offered as output;
- WebP is currently input-only;
- fast splitting accepts H.264 MP4/MOV with AAC audio or no audio;
- fast splitting depends on existing source keyframes and fails safely when the selected limits cannot be met;
- RAW, animated-image output, precise re-encoded splitting, general editing/merging, and natural-language commands are not implemented;
- platform presets for services such as WeChat, Bilibili, or Discord are not published until their rules can be verified.
## Build from source
Requirements: macOS 15+, Xcode 16.4+, and Swift 6.
```sh
xcodebuild -project FileIsland.xcodeproj \
-scheme FileIsland \
-destination 'platform=macOS' \
-derivedDataPath .build/DerivedData \
CODE_SIGNING_ALLOWED=NO \
build
```
```sh
xcodebuild -project FileIsland.xcodeproj \
-scheme FileIsland \
-destination 'platform=macOS' \
-derivedDataPath .build/DerivedData \
CODE_SIGNING_ALLOWED=NO \
test
```
## Command-line interface
Build the shared `FileIslandCLI` scheme. Keep these five adjacent runtime files together: `fileisland`, `ffmpeg`, `ffprobe`, `FileIslandMediaValidator`, and `built-in-presets.json`.
```sh
xcodebuild -project FileIsland.xcodeproj \
-scheme FileIslandCLI \
-destination 'platform=macOS' \
-derivedDataPath .build/DerivedData \
CODE_SIGNING_ALLOWED=NO \
build
```
Always query the machine-readable capabilities before generating a call:
```sh
.build/DerivedData/Build/Products/Debug/fileisland capabilities --json
```
Convert a heterogeneous folder:
```sh
.build/DerivedData/Build/Products/Debug/fileisland convert \
'/path/input folder' --recursive \
--output '/path/output folder' \
--image-format jpeg --image-max-dimension 2048 --strip-metadata \
--video-resolution 1080p \
--audio-format m4a --audio-quality balanced --strip-audio-metadata \
--json
```
Split an eligible video at safe keyframes without re-encoding:
```sh
.build/DerivedData/Build/Products/Debug/fileisland split \
'/path/movie.mp4' \
--output '/path/output folder' \
--max-duration-seconds 300 \
--mode fast-keyframe-copy \
--json
```
The CLI uses the caller's filesystem permissions and does not reuse the app's saved output-folder bookmark. Sources are never overwritten. Exit codes and exact options are reported by `--help` and `capabilities --json`.
## Privacy, licensing, and feedback
File Island is **source-available, not open source**. Original code, branding, and assets are All Rights Reserved under [`LICENSE`](LICENSE). Bundled FFmpeg remains independently available under LGPL-2.1-or-later.
- [User guide](docs/USER_GUIDE.md)
- [Format matrix](docs/FORMAT_MATRIX.md)
- [Changelog](CHANGELOG.md)
- [Privacy policy](PRIVACY.md)
- [Security reporting](SECURITY.md)
- [Third-party notices](Legal/THIRD_PARTY_NOTICES.md)
- [FFmpeg build and source record](Legal/FFMPEG_BUILD.md)
Use [GitHub Issues](https://github.com/TREAFREE/FileIsland/issues) for ordinary bug reports. Report unresolved security issues privately as described in [`SECURITY.md`](SECURITY.md), and do not attach private media to public issues.