Smaller App Size

A "Hello World" desktop app built with Electron often weighs in at over 100 MB before it does anything useful. That overhead comes from bundling an entire Chromium browser and a Node.js runtime with every application. For users on metered connections, low-end hardware, or just impatient to try your software, that bloat is a real adoption barrier.

Tauri’s answer is not to optimise around the bloat — it removes the bloat altogether. A minimal Tauri application can be under 600 KB, and even a feature‑complete tool often stays below 15 MB. This page explains the architectural decisions that make that possible, how the numbers compare in practice, and what you can do to keep your own builds lean.

Why App Size Matters

Download size affects every stage of a user’s relationship with your software. A large installer increases the chance someone abandons the download halfway through. Automatic updates become slower and more expensive to distribute. On Linux, where AppImage or Flatpak bundles can pull in system dependencies, the difference between a 6 MB package and a 200 MB one is felt immediately.

Beyond the download, disk footprint matters in shared or space‑constrained environments — think thin clients, virtual machines, or embedded systems. A smaller app also leaves a smaller surface for disk‑I/O during startup, though the main win is the initial acquisition.

How Tauri Keeps Apps Small

Three deliberate design choices account for nearly all of the size reduction.

No Browser Engine Is Shipped

Electron bundles Chromium so that every user gets the same rendering environment. Tauri instead uses the operating system’s built‑in webview: WebView2 on Windows, WKWebView on macOS and iOS, WebKitGTK on Linux, and Android System WebView on Android. Those components are already present on the system and maintained by the OS vendor, so Tauri never needs to ship a copy.

This single decision removes the largest contributor to a desktop app’s bundle size. Chromium alone can account for 100–150 MB of an Electron distribution, and that cost repeats with every application that uses Electron.

No JavaScript Runtime Is Bundled

In Electron, the backend process runs Node.js — meaning the Node.js runtime must be packed alongside Chromium. Tauri’s backend is written in Rust and compiled to a native binary. There is no interpreter or runtime to distribute, and the binary only contains the code paths your app actually exercises.

Rust Produces Efficient Native Binaries

Rust’s compilation model, zero‑cost abstractions, and lack of a garbage collector result in small executables even without deliberate size tuning. When you add the optimisations described later in this page, the core Tauri scaffolding adds only a few hundred kilobytes to the final binary. The remaining size comes from your own Rust logic and the frontend assets you embed.

Size Comparison: Tauri vs Electron

Real‑world numbers vary with the frontend framework, Rust dependencies, and packaging format, but the gap is consistent. The table below draws from published benchmarks and community reports (for an expanded breakdown, see the Comparison Table).

The AppImage range for Tauri is wider because it can optionally bundle multimedia frameworks like GStreamer, which pulls in additional libraries. Even then, the resulting image is still a fraction of what a comparable Electron AppImage would weigh.

What Goes Into a Tauri Bundle

Understanding the final bundle helps when you set size expectations for your own project.

A Tauri desktop release (for example a macOS .app or a Windows .exe installer) consists of:

1. The Rust executable – contains the Tauri runtime, your command handlers, and the frontend assets embedded directly into the binary. Tauri uses tauri::include_dir! or similar mechanisms to bake HTML, CSS, and JavaScript into the executable, so there are no loose files to manage.
2. Platform‑specific wrapper – on macOS, the .app bundle includes an Info.plist and the application icon. On Windows, the installer (.msi or NSIS) adds registry entries and uninstaller logic. These wrappers typically add only a few hundred kilobytes.
3. Optional sidecars – if you bundle external binaries (e.g., a standalone media encoder or a local server; see Understanding Sidecars), they sit alongside the executable and contribute their own size.
4. System libraries (AppImage) – on Linux, an AppImage bundles any shared libraries your app needs that are not guaranteed on the target system. This can raise the size from a few megabytes to 50–70 MB or more if frameworks like GStreamer are included.

Optimising Your App Size

The Rust compiler gives you fine‑grained control over the trade‑off between binary size, runtime performance, and compilation time (for advanced build flags, visit Optimizing Builds). The following profiles are a practical starting point.

[profile.release]
codegen-units = 1          # Gives LLVM a whole-crate view for better inlining and dead code removal.
lto = true                 # Enables link-time optimisation across all crates.
opt-level = "s"            # Optimise for size (use "z" for even smaller, "3" for speed).
panic = "abort"            # Removes unwinding machinery, shrinking the binary.
strip = true               # Strips debug symbols from the final binary.

A few of these settings deserve a closer look:

• opt-level = "s" vs "z": "s" applies size optimisations that rarely hurt performance. "z" pushes even further but can sometimes produce measurably slower code, so test both if runtime speed matters.
• lto = true: Link‑time optimisation lets LLVM see across crate boundaries and eliminate a surprising amount of dead code. The cost is a longer build, especially on CI.
• panic = "abort": If a panic occurs, the process terminates immediately instead of unwinding the stack. This saves space but means you must handle errors gracefully — no catching panics with std::panic::catch_unwind in release mode.
• codegen-units = 1: The default (16) speeds up compile times by parallelising code generation. Reducing it to 1 gives LLVM more context and often reduces binary size by 10–20%, but compilation becomes noticeably slower.

Beyond the Rust profile, Tauri can trim unused command handlers from the binary. Add the following to your tauri.conf.json:

{
  "build": {
    "removeUnusedCommands": true
  }
}

When this flag is active, the Tauri CLI inspects your capability files and instructs the build script to exclude any command that is never explicitly allowed. The result is a smaller binary, especially in projects that depend on several plugins but only use a subset of their APIs.

Trade‑offs and Real‑World Sizes

Aiming for the smallest possible binary sometimes conflicts with other goals. Every optimisation you enable has a secondary effect.

• Compile time: lto = true and codegen-units = 1 make compilation meaningfully slower. During development, use the defaults in the [profile.dev] section and apply size tuning only for [profile.release].
• Debugging: panic = "abort" and strip = true remove information that is valuable when a user reports a crash. For closed‑beta or internal releases, you might maintain a separate profile that keeps debug info.
• Performance: opt-level = "s" is safe for most workloads, but CPU‑intensive Rust logic (e.g., video processing) may benefit from opt-level = 3 and a few extra kilobytes.
• Linux packaging: If you ship an AppImage, the runtime environment of your build machine dictates how many system libraries get bundled. Building on a newer distribution can silently raise the minimum glibc version and force the bundling of core libraries, ballooning the AppImage.

Even with these trade‑offs, the final binary for a typical Tauri app — say, a markdown editor with a React frontend, filesystem access, and an updater — is usually in the 5–15 MB range. That is an order of magnitude smaller than the equivalent Electron bundle.

Common Misconceptions

"Tauri apps are always under 1 MB."
The 600 KB baseline is for an empty shell. Every frontend framework, image, font, and Rust dependency adds weight. A production app will be larger, but the overhead added by Tauri itself remains tiny.

"Smaller size comes at the cost of inconsistent rendering."
Tauri uses different web engines on each OS — WebView2, WKWebView, WebKitGTK. While differences exist, they are the same engines that power Edge, Safari, and GNOME Web. Modern web standards mean the vast majority of your UI will look identical, and the engineering team actively patches gaps. The trade‑off is not "correctness vs size"; it is "a few kilobytes of platform‑specific CSS adjustments vs shipping 100 MB of Chromium."

"I need to learn Rust's linker tricks to get a small binary."
The Cargo profile shown above is all you need in most cases. Tauri’s build tooling already applies sensible defaults, and the removeUnusedCommands flag handles the application‑level dead code. Deep linker tuning is only required if you are pushing toward embedded‑level footprints.

The small size of a Tauri app is not a lucky accident; it is the cumulative result of relying on the platform’s own webview, compiling to native code, and giving you the compiler flags to trim what remains. From this foundation, Tauri builds upward with a flexible architecture that lets you choose any frontend stack and Rust libraries without undoing those gains.