FixIt 101 SketchUp Plugin: Remove Duplicate Edges & Faces

FixIt 101 (by Anton Synytsia) is one of the most downloaded legacy SketchUp plugins for automatic mesh cleanup — it removes duplicate faces in SketchUp, eliminates stray edges, merges coplanar faces, and attempts to close open solids in a single click. Unlike general-purpose cleanup tools, FixIt 101 focuses specifically on the three geometry problems that most commonly prevent a SketchUp group or component from passing the solid test: internal faces that got trapped inside a shape during boolean operations or imports, doubled-up edges that appear when geometry is copy-pasted over existing faces, and tiny disconnected edge segments left behind after exploding or intersecting surfaces. The plugin works by scanning every entity inside selected groups and components, then applying a fixed sequence of repairs in the right order — coplanar merging before hole-filling — so that each step does not undo the previous one. The result is a clean, manifold solid that WooCommerce (3D printing exporters), LayOut section fills, and IFC exporters can all consume without complaint.

Despite being last updated in 2014 (version 1.5.0), FixIt 101 is a single pure-Ruby script with no compiled C extensions or OS-level binaries. Because SketchUp’s Ruby API surface has stayed largely stable for geometry operations, the plugin loads and runs correctly on SketchUp 2017 through 2025. You will not find it in the Extension Warehouse — the .rbz must be downloaded manually (link at the bottom of this post) and installed through Extensions > Extension Manager > Install Extension. Once installed it appears under Extensions > FixIt 101 with a single menu item.

This post explains every feature in detail, documents the known edge cases that can produce unexpected results, and compares FixIt 101 with actively maintained alternatives so you can decide which tool fits your workflow.

Key Features

• Remove duplicate and internal faces. When you use Intersect Faces or import geometry from DWG/OBJ, SketchUp frequently creates faces that occupy the same plane as an existing face, or faces that exist entirely inside a solid mesh. FixIt 101 detects both cases — same-plane duplicates and fully interior faces — and deletes them. This is the most impactful operation for 3D-printing workflows: interior faces confuse slicers into generating support structures or infill patterns where none are needed.
• Merge coplanar faces. Complex boolean operations and dense imported CAD geometry produce dozens of triangles where a single flat polygon should exist. FixIt 101 dissolves the shared edges between any two adjacent faces whose normals are parallel, replacing the triangulated mesh with the minimal polygon set. This reduces face count, speeds up rendering, and makes the model far easier to edit — unnecessary edges no longer interrupt the Push/Pull tool or split texture UVs.
• Remove stray (single) edges and repair split edges. Stray edges are edges not connected to any face. They appear after Erase operations that miss a follow-me segment, or after exploding components whose bounding edges had no corresponding face. Split edges — a single logical edge represented as two collinear edge segments sharing a midpoint vertex — are common after importing SVG paths or DWG geometry. FixIt 101 removes the orphaned edges and welds the collinear pairs back into single edges.
• Add missing faces to close open solids. SketchUp defines a “solid” as a group or component where every edge is shared by exactly two faces — no more, no fewer. When a face is accidentally deleted or was never generated during import, the solid has a “hole” and will not pass the solid test. FixIt 101 scans for edges bounding fewer than two faces and attempts to reconstruct the missing planar face by finding the boundary loop. This works reliably for flat, planar holes (a missing top face on a box) but is less reliable for curved or non-planar openings.
• One-click, selection-aware operation. The plugin reads your current selection state at the time you run it. If you have one or more groups or components selected, it repairs only those entities. If nothing is selected, it processes every group and component in the entire model. This selection-awareness is the primary workflow control — it is not a dialog-driven tool with per-operation toggles.
• Pure Ruby, no dependencies. The entire plugin is a single .rb file (under 10 KB). It has no gem dependencies, no compiled extension, and no internet connection requirement. Installation is offline, and it will not conflict with other plugins at the Ruby level.

How to Install and Use

1. Download the .rbz file. Click the Download link at the bottom of this post to get FixIt_101.rbz. Save it to a location you can find — your Desktop or Downloads folder is fine.
2. Open Extension Manager. In SketchUp, go to Extensions > Extension Manager (SketchUp 2017+) or Window > Extension Manager (older versions). Click the red Install Extension button in the lower-left corner.
3. Select the .rbz. Navigate to where you saved FixIt_101.rbz and open it. SketchUp will ask if you trust the source — click Yes. The extension appears in the list immediately; no restart required.
4. Select what you want to fix (recommended). Before running the plugin, select the specific group(s) or component(s) you want to repair. Triple-click a group to select all its geometry and then use Edit > Select All (Ctrl+A) if you want the entire group, or simply click the group bounding box once to select the group entity itself. Selecting before running is almost always safer than letting the plugin process the entire file — see the Pro Tips section for why.
5. Run the plugin. Go to Extensions > FixIt 101. The plugin runs synchronously — there is no progress bar. For typical architectural models with a few hundred thousand faces, the operation completes in under a second. For very large scenes (millions of faces) it can take several seconds; SketchUp will appear frozen during this time but will recover.
6. Verify the result with Entity Info. After running, click on the repaired group and open Window > Entity Info. If the volume field is populated (e.g., “Volume: 4.2 m³”) the group is now a valid solid. If Entity Info shows no volume, the solid still has open edges — at this point Thomas Thomassen’s Solid Inspector² is the best next step, as it visually highlights exactly which edges are still problematic.
7. Undo if needed. The plugin registers its operations as a single undo step. If the result looks wrong — for example, glass faces inside a window frame were deleted — press Ctrl+Z once to revert the entire operation.

Pro Tips

• Always select before running on complex scenes. The most common complaint about FixIt 101 is that it deletes window glass or thin single-face partitions. The reason: a flat face with no connecting faces on either side looks identical to an interior face from the plugin’s perspective — both are faces that are not part of a closed solid boundary. If you run the plugin without selection on a scene containing both solid objects and intentional single-face sheets, the sheets will be removed. Selecting only the solid groups you want repaired prevents this entirely.
• Run FixIt 101 before Solid Inspector², not after. Solid Inspector² shows you the current list of open edges and interior faces but does not repair them. FixIt 101 fixes what it can automatically. The efficient workflow is: FixIt 101 first (handles 80–90% of cases automatically), then Solid Inspector² to see what remains, then manual repair for the complex open edges that FixIt could not reconstruct.
• Use it after DWG/DXF imports. CAD imports are the single biggest source of duplicate faces and stray edges in SketchUp. AutoCAD geometry often contains overlapping linework that SketchUp converts into stacked edges and duplicate coplanar faces. Running FixIt 101 immediately after importing a DWG — before you start modeling on top of it — clears the baseline noise and makes the imported geometry far easier to work with.
• Do not run it on geometry with intentional triangulation (e.g., subdivided organic meshes). The coplanar face merging step will dissolve every shared edge between coplanar triangles. For organic subdivision-surface models this usually produces large, irregular polygons that are harder to edit than the original triangulation. Apply FixIt 101 only to hard-surface architectural or mechanical geometry where the “intended” shape is flat faces and clean corners.
• Combine with CleanUp³ for a full model hygiene pass. FixIt 101 targets solid geometry repair. CleanUp³ (Thomas Thomassen, Extension Warehouse, free) adds what FixIt does not cover: removing unused layers, purging unused components and materials, and removing small faces below a threshold size. Running FixIt 101 first (solid repair) and then CleanUp³ (file size reduction) gives you a clean, lightweight model ready for rendering or export.

System Requirements

• SketchUp version: 2017 or later (tested through SketchUp 2025). The plugin also loads on older versions (2014–2016) but these are no longer officially supported.
• Operating system: Windows 10/11 or macOS 10.14 Mojave and later. Because the plugin is pure Ruby with no compiled component, it runs identically on both platforms.
• SketchUp edition: Works on SketchUp Free (web) only with .rb sideload, which is unsupported. Reliable installation requires SketchUp Go, Pro, or Studio (desktop). The Extension Manager .rbz installation path is available in all paid desktop editions.
• Dependencies: None. No additional gems or libraries required.

Download FixIt 101

Nguyen Huu Khanh

Architect turned developer