Unity Size Explorer Tips: Best Practices for Smaller Builds

Unity Size Explorer Tutorial: Find and Fix Large Assets

What Unity Size Explorer is

Unity Size Explorer is a tool (part of Unity or available as a package) that analyzes your project’s build to show how much space each asset, folder, and bundle consumes. It helps identify large textures, audio, or models that drive up build size so you can prioritize optimizations.

Why use it

• Find size hotspots quickly instead of guessing.
• Prioritize fixes that yield the largest size savings.
• Compare builds to track regressions over time.

Quick step-by-step: analyze a build

1. Install or open Size Explorer (assume package or menu item in Unity Editor).
2. Generate a build report: make a development build or use the Editor’s build report/export feature.
3. Load the build report into Size Explorer (drag the report or use “Open Report”).
4. Scan the tree view to find top folders, bundles, and assets by size.
5. Sort/filter by size, asset type, or modified date to narrow candidates.

Common fixes for large assets

• Textures: lower resolution, change compression (e.g., ASTC/ETC2), use mipmaps only when needed.
• Audio: convert WAV → compressed (Ogg/Vorbis/MP3), reduce sample rate, trim silence, use streaming for long clips.
• Meshes: simplify meshes, remove unused blendshapes, use LODs and combine small meshes.
• Shaders & Materials: remove unused shader variants, share materials, use simpler shaders for mobile.
• Asset duplication: use Addressables or Resources wisely; reference shared assets instead of duplicates.

Workflow tips

• Target top 80%: focus on assets that make up the largest portion of size.
• Make incremental builds and compare reports to verify savings.
• Automate checks in CI to catch regressions.
• Document decisions (why a texture was downscaled, compression chosen).

Example quick fixes (concrete)

• Convert a 4k UI atlas to 2k and switch to ASTC 6×6 → ~60–80% texture size reduction.
• Re-encode background music from WAV (50 MB) to Ogg at 128 kbps → ~95% reduction.
• Merge ten small mesh objects into a single mesh where dynamic occlusion isn’t required → fewer draw calls and reduced mesh overhead.

When to re-check

• After adding new art or audio batches.
• Before releasing to store or creating platform-specific builds.
• When build size suddenly increases in a commit.

Useful metrics to watch

• Total build size, top 10 assets size, compressed vs uncompressed size, per-platform differences.

If you want, I can:

• provide a short checklist tailored to a Unity platform (Android/iOS/PC), or
• walk through optimizing a specific asset if you share its type and size.