Speeding up the Unreal Editor Launch by Not Spawning 38,000 Tooltips? Unreal Engine has evolved into a feature-rich platform beyond a game engine, encompassing games, movies, live content, VFX, and more. This growth has led to one frustrating issue: long editor startup times. Current Measures to Reduce Startup Time Live coding (hot-reloading) to avoid restarting the editor Derived data caches to skip asset preparation Using simplified levels to reduce assets loaded on startup While helpful, these measures depend on project specifics and manual effort. --- Investigating Startup Performance An exploration into the editor’s startup uncovered a surprising bottleneck: the spawning of tooltip widgets. The function SetToolTipText not only sets tooltip text but fully spawns a tooltip widget with all its sub-widgets. Unreal Engine creates tooltips for all widgets in the editor, approximately 38,000 tooltips for a simple project. In UE 5.6, tooltip text storage improved but the number of tooltips remained huge. On startup, this can add 2-5 seconds of delay in debug builds and consumes about 40 MB of RAM for tooltip widgets. Why Is This a Problem? Most tooltips are never actually shown—only a few dozen are used typically. The editor wastes time and memory spawning thousands of unused tooltip widgets. This inefficiency was verified by profiling tools, showing significant time spent in tooltip creation. --- Proposed Solution: Lazy Tooltip Widget Creation Instead of spawning tooltip widgets immediately when the text is set: Save the tooltip text only when SetToolTipText is called. Postpone the actual tooltip widget creation to when a tooltip is actually requested via GetToolTip. This minimizes costly widget creation during startup and defers it to runtime only when needed. Runtime Impact Practically no negative runtime impact because: The user can only hover over one widget at a time, so tooltips are created one by one on demand. Single tooltip creation is very fast (~0.05 ms in debug builds). Vast amount of wasted creation is eliminated, speeding up startup without runtime slowdown. --- Additional Notes A pull request with these changes is available for testing: UnrealEngine PR #13739. An update from Nick Darnell revealed most tooltips come from optional project settings and editor preferences panels, around 20,000 tooltips combined. Closing or removing rarely used panels/layout elements can also reduce tooltip spawning and shorten editor launch times. --- Summary Unreal Editor spawns an excessive number of tooltip widgets on startup, causing long delays and high memory use. Changing tooltip creation to be lazy—only creating widgets when needed—significantly speeds up startup with negligible runtime cost. Many tooltips originate from optional UI panels, so customizing the editor layout can further improve load times. The improvement requires minimal code changes and could be considered for integration into future Unreal Engine releases. --- If you want to keep up with more insights, you can follow the author on BlueSky, Mastodon, or LinkedIn, or subscribe to the blog. --- Related Articles by the Author Profiling Trackmania stuttering without source code Upgrading Unreal’s Static Mesh Editor Memory savings by removing multiplayer components Fixing Unreal Editor frame spikes due to Windows waiting --- This article provides a practical and effective way to reduce Unreal Editor startup delays by addressing an overlooked inefficiency in tooltip widget creation.