Render Profiler

Render Profiler is a Blender add-on that profiles and analyzes render and viewport performance. It opens a live HTML report in your browser with modifier timings, mesh and texture data, memory estimates, statistics and keeps synced with Blender.

Usage

Where to find it?

• Topbar → Window → Render Profiler Report
• Or from the File context menu (F4): Render Profiler Report

The report opens in a web browser and refreshes automatically.

How to get information about rendering?

By default, the profiler shows data from the viewport. If you want to get information from a render:

1. Switch the profiler to render mode by clicking Render on the report page.

2. Press F12 in Blender to start the rendering process. Once the data is initialized, it will be available in the profiler.

Topbar indicator

When profiling is on (Viewport or Render), the top bar shows a short line: Profiling (Viewport) or Profiling (Render) with X button. Use X to turn profiling off or press on indicator to open new report page in the browser.

Modes (mode switcher in the report)

• Off – Profiler disabled. No data collection.
• Viewport – Collects data on viewport updates (e.g. selection, transforms). Data updates as you work.
• Render – Collects data when a render is started (from the render data). Use for renderer analysis.

Performance Notice: Data collection adds some overhead, so slightly worse performance while profiling is expected. If you have issues, consider pressing Off in the report to stop scene profiling and use profiler on demand.

Current Limitations:

• Profiler doesn't show exact memory usage, instead it tries to estimate values based on scene data
• Volumes are listed in the Memory tab but memory calculation is not supported.
• Images with RGBA16F pixel format are treated as RGBA32F

Tabs

• Modifier times — Per-object modifier execution time (ms/s). Objects with modifiers, sorted by total time.
• Heavy meshes — Mesh size: vertices, edges, faces, triangles. Sorted by triangle count. Instance count shown.
• Memory — Unified table of estimated memory: meshes, textures, curves, sorted by estimated size. Volumes are not supported.
• Textures — Texture (image) memory used by at least one object in scene view layer or world: name, materials, size (KB/MB), dimensions.
• Statistics — Combined totals: modifier time, vertices/edges/faces/triangles, object and instance counts, texture memory total, dependency graph debug stats.

Preferences

• Edit → Preferences → Add-ons → Render Profiler
• Report font size – Base font size for the report page. Reopen the report to apply.

Technical notes

• The report server runs in a background thread and listens on a local port (default 8765). Only one report window is intended; reopening reuse the same server.
• Data is collected from the evaluated dependency graph (viewport or render, depending on mode).
• Modifier execution times are per object; parallel execution is not reflected in the sum.
• The report uses Blender’s default font (Inter) and icons converted from official blender icons set.

Memory size calculation

The Memory tab shows estimated memory for geometry and textures.

Mesh

• Base geometry:
  • Vertex: vec3 float (position) = 12 bytes each.
  • Edge: 2 ints = 8 bytes each.
  • Loop: vertex_index + edge_index (2 ints) + normal (vec3 float) = 20 bytes each.
  • Polygon: 4 ints (loop range, typical quad) = 16 bytes each.
• Attributes (UV, vertex color, Geometry Nodes attributes) are counted only when used in at least one material node (domain_size × element_bytes).

Texture

• Image memory: width × height × (depth/8) bytes, where depth is the image bit depth (e.g. 8) multiplied by channels. Only images used by at least one object in scene active view layer or the scene world are included.
• Current limitations: Images with RGBA16F pixel format are treated as RGBA32F

Curves (hair / Geometry Nodes)

• Per point: position (3 float) + radius (1 float) + normal (3 float) = 28 bytes.
• Per curve: 4 bytes (offset in point array).
• Total = points × 28 + curves × 4.

Volume

• Volumes are listed in the Memory tab but memory calculation is not supported.

Links

• Website: https://t.me/multlabs
• Support: https://blenderartists.org/t/render-profiler/1632393