LocalSend for Android 4.4 · 安卓 4.4 版

An unofficial community fork of LocalSend that runs on old Android — from Android 4.4 KitKat (API 19) all the way to modern Android.
一个非官方社区分支,让 LocalSend 重新运行在老旧安卓上 —— 从 Android 4.4 KitKat(API 19) 一直到最新 Android。

🌐 English ｜中文

📥 Download / 下载

Click a file to download directly · 点击文件名即可直接下载:

APK	minSdk	For / 适用设备
LocalSend-1.15.1.6fix-android-arm64-v8a.apk	21	64-bit phones, Android 5.0+ · 64 位手机(安卓 5.0+)
LocalSend-1.15.1.6fix-android4.4-armeabi-v7a.apk	19	32-bit / old devices incl. Android 4.4 · 32 位 / 老设备,含安卓 4.4 KitKat

Both are version 1.15.1.6fix. Package org.localsend.localsend_app.android44 — installs alongside the official LocalSend. To sideload, enable "Install unknown apps" in Settings. See all files on the Releases page.

两个包都是 1.15.1.6fix,包名为 org.localsend.localsend_app.android44,可与官方版共存。侧载需在系统设置里允许「安装未知应用」。全部文件见 Releases 页面。

English

What is LocalSend?

LocalSend is an open-source, cross-platform alternative to AirDrop. It lets you send files, photos, and text between devices on the same local network — no internet, no account, no cloud.

Transfers go over an encrypted (TLS) HTTP connection.
Devices find each other automatically using UDP multicast discovery.
Nothing leaves your local network.

This fork keeps all of that and makes it work on Android 4.4+.

Features

Everything from upstream LocalSend v1.15.1, plus:

📁 Send files, photos, and text between devices on the same network.
🔒 Encrypted (TLS) transfers — no internet or account required.
📡 Automatic device discovery via UDP multicast.
🌍 Cross-platform — interoperates with LocalSend on Windows, macOS, Linux, iOS, and Android (incl. the official desktop apps).
🎨 NEW: Custom theme color.
📂 NEW: In-app folder/file picker on Android 4.4 — “send an entire folder” now works on KitKat.

Custom theme color (new in this fork)

Android below 12 can't read the system accent color (Material You / dynamic color needs Android 12+), so on KitKat the app was stuck with a fixed teal theme. This fork adds a manual color picker:

Settings → Color shows a row of 12 preset swatches: teal (default), blue, indigo, deep purple, pink, red, deep orange, amber, green, cyan, brown, blue grey.
Tap one and the whole app re-themes instantly (light & dark).
The color is used as the Material 3 seed color and is saved (in SharedPreferences).

In-app folder/file browser (new in this fork)

The system folder picker (the Storage Access Framework's ACTION_OPEN_DOCUMENT_TREE) is API 21+, so on Android 4.4 "send an entire folder" used to be unavailable. Below API 21 the file and folder pickers now open a small built-in Material 3 browser instead:

It reads storage directly with dart:io — on KitKat READ_EXTERNAL_STORAGE is granted at install time and there's no scoped storage.
Folder mode: pick a folder and its whole tree is sent recursively.
File mode: multi-select individual files with checkboxes.
Android 5.0+ is unchanged — it keeps using the system SAF pickers.

Why v1.15.1? (the version ceiling)

v1.15.1 is the highest upstream version that actually runs on Android 4.4:

v1.16.0+ is impossible on 4.4 — it added a Rust HTTP client (rhttp, needs API 21+) and requires Dart ≥ 3.5 / Flutter ≥ 3.24, but Flutter 3.22+ dropped KitKat (API 19/20) entirely.
v1.15.2 / 1.15.3 / 1.15.4 crash on 4.4 — v1.15.2 moved discovery into a background Dart isolate (PR "Discover in different thread #1555"). That code, AOT-compiled for armeabi-v7a, triggers a Dart AOT compiler bug → native SIGSEGV in libflutter.so at the first frame. Confirmed by bisecting all four versions on real hardware: v1.15.1 runs; 1.15.2/3/4 all crash.

So v1.15.1 is the definitive working ceiling (it already includes upstream fixes for the ">2 GB transfer" crash and the Android TV picker crash). Newer 1.16.0+/2.x code can't be cleanly back-ported (it's built on the diverged Rust/rhttp + Flutter 3.24 + HttpServer + isolate codebase).

What works on KitKat

Capability	Android 4.4
Receive files / photos / text	✅
Send individual files / media / text	✅
Device discovery + transfer	✅
Send an entire folder	✅ (in-app picker)
Choose the receive/save folder	✅ (in-app picker)

Folder picking on 4.4: the system Storage Access Framework directory picker (ACTION_OPEN_DOCUMENT_TREE) is API 21+, so on KitKat the app falls back to a small built-in Material 3 file/folder browser that reads storage directly via dart:io (READ_EXTERNAL_STORAGE is install-granted and there's no scoped storage below API 21). It backs sending a whole folder (sent recursively), the multi-select file picker, and the receive-destination "save folder" setting. The browser has a large, tablet-friendly layout with an editable address bar (type a path to jump). Android 5.0+ keeps using the system SAF picker unchanged.

Back-ported fixes (the "6fix")

Six small, isolate-independent fixes cherry-picked onto v1.15.1:

Receive large files without OOM (PR #1547) — flush to disk every 10 MB instead of buffering the whole file in RAM.
Send large files without OOM (PR #1661) — stream via a managed StreamController instead of .asBroadcastStream().
Any absolute URI is clickable (PR #1662) — file://, obsidian://, etc., not just http(s).
Tooltip on the "Scan" button (from v1.15.4).
Path-traversal security fix (from v1.17.0) — rejects ../ in a file name that would write outside the download folder (p.isWithin check).
Duplicate text-message fix (PR #2296) — a received text was shown three times in the history dialog.

Android-compatibility changes (vs stock v1.15.1)

minSdkVersion 21 → 19 (the arm64-v8a build uses 21).
Multidex enabled (MultiDexApplication) — below API 21 the ~50 plugins exceed the 64K-method single-dex limit.
In-app file/folder browser on KitKat: below API 21 the file and folder pickers route to a built-in Material 3 browser (dart:io direct filesystem access) instead of the API-21+ SAF picker; API 21+ is unchanged. The native MainActivity SAF "pick a folder" paths remain guarded as a fallback.
Distinct applicationId (org.localsend.localsend_app.android44) so it coexists with the official app.
Aliyun maven mirrors for Gradle (China network only); Gradle daemon/parallelism disabled for low-RAM builds.

Reference / test device

Verified to launch and run on a Xiaomi Redmi Note 1 — Android 4.4.4 KitKat, armeabi-v7a (32-bit): the app launches, the UI renders, and discovery + transfer work.

Build from source

Toolchain: Flutter 3.13.9 (pinned in .fvmrc), Dart 3.1.x, JDK 17, Android platform-34 + build-tools 34.0.0, AGP 7.2.0, Gradle 7.5.

# armeabi-v7a (Android 4.4+), minSdk 19
flutter build apk --release --target-platform android-arm --build-name=1.15.1.6fix --build-number=50
# arm64-v8a (Android 5.0+): set minSdkVersion 21 in app/android/app/build.gradle first
flutter build apk --release --target-platform android-arm64 --build-name=1.15.1.6fix --build-number=50

Credits & License

A fork of the official LocalSend by Tien Do Nam and contributors — all credit for LocalSend goes to the upstream project. Licensed under the MIT License, Copyright (c) 2022-2024 Tien Do Nam; this fork keeps the original license and copyright (see LICENSE).

Unofficial community build. Not affiliated with or endorsed by the official LocalSend project. Provided "as is," without warranty.

中文

LocalSend 是什么?

LocalSend 是一个开源、跨平台的 AirDrop 替代方案,让你在同一局域网内的设备之间发送文件、照片和文本 —— 无需联网、无需账号、无需云端。

传输通过加密(TLS)的 HTTP 连接进行。
设备之间通过 UDP 组播(multicast)自动发现。
数据不会离开你的局域网。

本分支保留了以上全部能力,并让它能运行在 Android 4.4 及以上的设备上。

功能特性

包含官方 LocalSend v1.15.1 的全部功能,并新增:

📁 在同一网络的设备间发送文件、照片和文本。
🔒 加密(TLS) 传输 —— 无需联网、无需账号。
📡 通过 UDP 组播自动发现设备。
🌍 跨平台 —— 可与 Windows、macOS、Linux、iOS、Android 上的 LocalSend(含官方桌面版)互通。
🎨 新增:自定义主题颜色。
📂 新增:安卓 4.4 应用内文件/文件夹选择器 —— 让「发送整个文件夹」在 KitKat 上可用。

自定义主题颜色(本分支新增)

Android 12 以下读不到系统强调色(Material You / 动态取色需要 Android 12+),所以 KitKat 上主题一直被固定为青色。本分支新增了一个手动取色器:

进入 设置 → 颜色,会看到一行 12 个预设色块:青色(默认)、蓝、靛蓝、深紫、粉、红、深橙、琥珀、绿、青蓝、棕、蓝灰。
点任意一个,整个应用立即重新着色(浅色 / 深色都生效)。
所选颜色作为 Material 3 的种子色,并持久化保存(存于 SharedPreferences)。

应用内文件/文件夹浏览器(本分支新增)

系统的文件夹选择器(SAF 的 ACTION_OPEN_DOCUMENT_TREE)是 API 21+,所以在安卓 4.4 上「发送整个文件夹」一直不可用。现在 API 21 以下,文件和文件夹选择会改为打开一个内置的 Material 3 浏览器:

通过 dart:io 直接读取存储 —— KitKat 上 READ_EXTERNAL_STORAGE 安装即授权,且没有分区存储。
文件夹模式: 选中一个文件夹,整棵目录树会被递归发送。
文件模式: 用复选框多选单个文件。
安卓 5.0+ 不受影响 —— 仍使用系统 SAF 选择器。

为什么是 v1.15.1?(版本天花板)

v1.15.1 是官方版本中能真正在 Android 4.4 上运行的最高版本:

v1.16.0+ 在 4.4 上根本不可能 —— 引入了 Rust HTTP 客户端(rhttp,需 API 21+),并要求 Dart ≥ 3.5 / Flutter ≥ 3.24,而 Flutter 3.22+ 已完全移除对 KitKat(API 19/20)的支持。
v1.15.2 / 1.15.3 / 1.15.4 在 4.4 上崩溃 —— v1.15.2 把网络发现移进了后台 Dart isolate(PR "Discover in different thread #1555")。这段代码为 armeabi-v7a 做 AOT 编译后,会触发 Dart AOT 编译器 bug → libflutter.so 内在第一帧发生原生 SIGSEGV。已在真机上对四个版本逐一二分验证:v1.15.1 可运行,1.15.2/3/4 全崩。

所以 v1.15.1 是确定的可用天花板(它已包含官方对 ">2 GB 文件传输崩溃" 和 Android TV 选择器崩溃的修复)。1.16.0+/2.x 的更新内容无法干净回移植(都建立在分叉后的 Rust/rhttp + Flutter 3.24 + HttpServer + isolate 代码库之上)。

KitKat 上哪些功能可用

能力	Android 4.4
接收文件 / 照片 / 文本	✅
发送单个文件 / 媒体 / 文本	✅
设备发现 + 传输	✅
发送整个文件夹	✅（应用内浏览器）
选择接收/保存目录	✅（应用内浏览器）

4.4 上的文件夹选择: 系统 SAF 目录树选择器(ACTION_OPEN_DOCUMENT_TREE)属于 API 21+,所以在 KitKat 上改用内置的 Material 3 文件/文件夹浏览器,通过 dart:io 直接读取存储(API 21 以下 READ_EXTERNAL_STORAGE 安装即授权、无分区存储)。它同时支撑:发送整个文件夹(递归)、多选文件、以及接收的「保存目录」设置。浏览器采用适配平板的大尺寸布局,并带可编辑地址栏(输入路径直接跳转)。安卓 5.0+ 仍走系统 SAF 选择器,行为不变。

已回移植的修复("6fix")

在 v1.15.1 之上挑选了 6 个与 isolate 无关的小修复:

接收大文件不再 OOM(官方 PR #1547)—— 每 10 MB 周期性刷盘,不再把整个文件缓存在内存。
发送大文件不再 OOM(官方 PR #1661)—— 用受管理的 StreamController 流式发送,取代会缓存整文件的 .asBroadcastStream()。
任意绝对 URI 可点击(官方 PR #1662)—— file://、obsidian:// 等也可点,不只 http(s)。
"扫描"按钮的提示气泡(取自 v1.15.4)。
路径穿越安全修复(从 v1.17.0 回移植)—— 拒绝文件名里用 ../ 把文件写到下载目录之外(p.isWithin 检查)。
文本消息重复显示修复(官方 PR #2296)—— 收到的一条文本曾在历史对话框里显示三次。

安卓兼容性改动(相对原版 v1.15.1)

minSdkVersion 由 21 降到 19(arm64-v8a 包用 21)。
启用 multidex(MultiDexApplication)—— API 21 以下约 50 个插件会超出 64K 方法的单 dex 上限。
KitKat 上的应用内文件/文件夹浏览器:API 21 以下,文件和文件夹选择改用内置的 Material 3 浏览器(dart:io 直接读文件系统),取代 API 21+ 的 SAF 选择器;API 21+ 不受影响。原生 MainActivity 的 SAF "选文件夹" 路径作为兜底仍保留保护。
使用独立包名org.localsend.localsend_app.android44,可与官方版共存。
为 Gradle 加阿里云 Maven 镜像(仅中国网络需要);关闭 Gradle daemon / 并行以适配低内存构建。

参考 / 测试设备

已在 红米 Note 1(Android 4.4.4 KitKat、armeabi-v7a 32 位)真机上验证:可正常启动、界面渲染、设备发现与传输。

从源码构建

工具链:Flutter 3.13.9(锁定于 .fvmrc)、Dart 3.1.x、JDK 17、Android platform-34 + build-tools 34.0.0、AGP 7.2.0、Gradle 7.5。

# armeabi-v7a(安卓 4.4+),minSdk 19
flutter build apk --release --target-platform android-arm --build-name=1.15.1.6fix --build-number=50
# arm64-v8a(安卓 5.0+):先把 app/android/app/build.gradle 里的 minSdkVersion 改成 21
flutter build apk --release --target-platform android-arm64 --build-name=1.15.1.6fix --build-number=50

致谢与许可证

非官方社区构建。 与官方 LocalSend 项目无隶属关系,也未获其认可。按"原样"提供,不附带任何担保。

Name		Name	Last commit message	Last commit date
app		app
common		common
scripts		scripts
.fvmrc		.fvmrc
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README.md		README.md

Navigation Menu

Repository files navigation

LocalSend for Android 4.4 · 安卓 4.4 版

📥 Download / 下载

English

What is LocalSend?

Features

Custom theme color (new in this fork)

In-app folder/file browser (new in this fork)

Why v1.15.1? (the version ceiling)

What works on KitKat

Back-ported fixes (the "6fix")

Android-compatibility changes (vs stock v1.15.1)

Reference / test device

Build from source

Credits & License

中文

LocalSend 是什么?

功能特性

自定义主题颜色(本分支新增)

应用内文件/文件夹浏览器(本分支新增)

为什么是 v1.15.1?(版本天花板)

KitKat 上哪些功能可用

已回移植的修复("6fix")

安卓兼容性改动(相对原版 v1.15.1)

参考 / 测试设备

从源码构建

致谢与许可证

About

Releases

Packages

Contributors

Languages

Latest commit

History

Folders and files

Repository files navigation

LocalSend for Android 4.4 · 安卓 4.4 版

📥 Download / 下载

English

What is LocalSend?

Features

Custom theme color (new in this fork)

In-app folder/file browser (new in this fork)

Why v1.15.1? (the version ceiling)

What works on KitKat

Back-ported fixes (the "6fix")

Android-compatibility changes (vs stock v1.15.1)

Reference / test device

Build from source

Credits & License

中文

LocalSend 是什么?

功能特性

自定义主题颜色(本分支新增)

应用内文件/文件夹浏览器(本分支新增)

为什么是 v1.15.1?(版本天花板)

KitKat 上哪些功能可用

已回移植的修复("6fix")

安卓兼容性改动(相对原版 v1.15.1)

参考 / 测试设备

从源码构建

致谢与许可证

About

Resources

Stars

Watchers

Forks

Releases

Packages

Contributors

Languages