Best Round Corner Plugin for SketchUp: BevelUp vs RoundCorner vs Bevel

SketchUp has no built-in fillet or chamfer command. The geometry engine makes this deliberate: SketchUp models from scratch using flat faces and clean edges, so a fillet operation would need to add faces that never existed — a fundamentally different task than modifying existing ones. The three tools below each solve this differently, and understanding why they work the way they do changes how you use them.

The most common misconception: Soften/Smooth Edges does not round geometry. It hides the edge line in the viewport and softens the shading transition, but the two flat faces on either side remain exactly flat. In any close-up render, the corner will still appear sharp because it is sharp. Actual rounded geometry requires inserting new faces between the originals — an arc cross-section swept along the edge — which is what every tool here does.

A second point that trips up new modelers: the bevel radius is constrained by the adjacent face width. If you try to put a 20 mm radius on an edge that borders a 10 mm panel, the bevel geometry cannot fit. Every tool handles this conflict differently — some skip the edge silently, some flag an error, some clamp the radius automatically.

BevelUp — Free, TypeScript Engine, UV-Preserving

BevelUp is the tool I built after running into a specific frustration: every existing option either required purchasing a license or ran through Ruby, which is slow enough on complex models to break the feedback loop. The approach I took was different — the computation runs in TypeScript inside SketchUp’s HtmlDialog, and the result is passed back to Ruby as a data payload for geometry creation.

The geometry engine is shapemetry, my own mesh kernel. The core function is bevel(mesh, edges, radius, segments) — it takes a mesh representation, a list of selected edges, a radius, and a segment count. When segments is 1, you get a flat chamfer (single angled face). When segments is 4 or more, you get a rounded arc approximated by that many subdivisions. The output is always triangulated, and edge softening is applied automatically.

UV preservation is where BevelUp does something no other free round corner tool does: it captures three UV anchor points per face before beveling, reconstructs the planar projection via a Gram matrix solve, and re-projects UV onto the newly created bevel faces. In practice this means a wood grain texture continues across the beveled edge rather than going blank or defaulting to the material color. The projection math reconstructs the original texture transformation from the three sample points, so it handles any texture scale, rotation, or offset that SketchUp was using — including materials applied via right-click texture position.

The smooth angle threshold defaults to 44°. Any shared edge between two output faces where the face-normal angle is 44° or less — meaning a dihedral angle of 136° or wider — gets soft and smooth flags set automatically. This removes the step of manually softening bevel edges after the operation. The threshold is not currently user-adjustable in the dialog (it is a code constant), but 44° covers most furniture and architectural use cases. A very tight radius with many segments may need manual softening on the transition edges if they fall near the threshold.

Gotchas specific to BevelUp:

• Requires SketchUp 2022 or later. The HtmlDialog JavaScript engine in earlier versions does not support the ES module features the TypeScript bundle uses.
• Login required. A free 3dshouse account is needed to unlock the tool — there is no paywall beyond that. No Pro tier, no feature limits.
• Output is triangulated. Ruby receives triangles from the bridge. BevelUp auto-hides and softens the coplanar edges between them, so the result looks like n-gons in the viewport, but internally the faces are triangles. If you later run operations that depend on face topology — such as a follow-me sweep using a bevel output face as the profile — be aware the face may be a triangle rather than the quad you expect.
• Radius is in model units. BevelUp reads the current model units from SketchUp and uses them. A radius of 5 means 5 mm if your model is in millimeters. This sounds obvious but causes confusion when files are exchanged between mm and inch workspaces.
• Nested groups and components. BevelUp operates on selected edges within the current editing context. To bevel edges inside a nested group, you need to open that group first. It does not traverse the component hierarchy automatically.

RoundCorner by Fredo6 — Three Modes, Ruby, Sketchucation

RoundCorner is the most widely used round-corner tool in SketchUp, maintained by Fredo6 (a prolific extension developer whose other work includes FredoScale, Curvizard, and ThruPaint). It costs $12 per license (or $40 for a bundle of all 8 Fredo6 plugins), distributed through the Sketchucation Plugin Store, and works in SketchUp 2017 through 2026. It is Ruby-based, which means the computation runs through the SketchUp interpreter — noticeably slower than a native extension on complex meshes, but sufficient for typical furniture and architecture work.

The main structural difference from BevelUp is the three-mode toolbar:

• Round — classic circular fillet. Adds a curved face (quarter-arc cross-section) along the selected edges. The arc is approximated by a configurable number of segments, typically 4 to 8 for furniture work, up to 24 for organic or product design.
• Bevel — flat chamfer. Adds a single angled face per edge, equivalent to BevelUp with segments set to 1. Produces a machined, furniture-grade look. Uses significantly fewer faces than Round mode, important for models going into CNC workflows where polygon count affects toolpath generation time.
• Sharp — no rounding. Reconstructs the corner geometry without adding a new face. Useful when other operations have left near-zero stray edges at corners and you want to clean them up without changing the silhouette. Most tutorials never mention this mode, but it solves a specific geometry-cleanup problem faster than manual edge deletion.

The offset value is the inscribed circle radius of the two faces meeting at the edge. If you set 10 mm, the transition face sits at 10 mm from the original edge. The hard geometric limit is approximately half the width of the shorter adjacent face — try to exceed it and RoundCorner either skips the edge silently or reports an error depending on the severity.

The per-edge highlight system is a workflow advantage not available in BevelUp. Before RoundCorner commits the geometry, it highlights every selected edge. Clicking an edge while in preview mode toggles it between orange (active) and red (excluded). This lets you round 90% of a model’s edges in a single operation and leave specific corners sharp — useful in cabinet work where back edges and pocket edges should never be rounded.

Gotchas specific to RoundCorner:

• Ruby performance on large meshes. On a component with 50,000+ faces, the per-edge processing loop in Ruby can take 15–30 seconds. BevelUp offloads this to TypeScript, which runs in a separate thread and does not block the SketchUp UI during computation.
• UV handling is not guaranteed. RoundCorner attempts to transfer material from adjacent faces onto the bevel face, but complex UV projections (texture position adjusted via right-click) may not carry correctly. Always inspect materials after rounding on textured models.
• Inside concave corners behave differently from outside convex corners. Round mode on a concave inside corner creates a curved face that bulges inward. This is geometrically correct but can look wrong on furniture panels where inside corners are usually left sharp. Use Bevel mode on concave edges to get a clean mitered inside corner instead.
• Requires LibFredo6. RoundCorner depends on Fredo6’s shared library extension. If you install RoundCorner on a fresh SketchUp, you also need LibFredo6 installed separately. Sketchucation’s Plugin Manager handles this automatically if you use it; manual .rbz installs require both files.

Bevel by Mind Sight Studios — $49, Live Non-Destructive Bevel

Bevel by Mind Sight Studios takes a fundamentally different approach from every other tool here: it offers Live Bevel — a non-destructive bevel applied to a group or component that updates automatically when the underlying geometry changes. Every other tool in this comparison is destructive: once the fillet geometry is created, editing the original shape requires undoing the bevel, modifying the mesh, then re-applying. Bevel eliminates that constraint entirely.

At $49 for a permanent license (free trial available at mindsightstudios.com), Bevel costs more than BevelUp (free), RoundCorner ($12), and Follow Me (built-in). Whether that premium is justified depends on your workflow — furniture going through multiple client review cycles, product models where base geometry changes late in the process, or parametric components that get resized repeatedly. For a one-off model, BevelUp handles the same operation for free.

Where Bevel stands out:

• Live Bevel — the only non-destructive option. Apply a bevel to a group or component once, then continue editing the geometry inside. Move faces, push panels, change proportions — the bevel updates automatically. No other round-corner tool for SketchUp does this. For design-heavy workflows where geometry changes late in the process, this eliminates the bevel-undo-edit-redo cycle entirely.
• Auto-soften and cleanup built in. Edge softening is handled automatically after applying — the same step that requires a manual Soften Edges pass in RoundCorner.
• Free trial before committing. Test the tool on real models before paying the $49 license.

Gotchas specific to Bevel:

• $49 is the highest price point here. Justified for iterative design workflows; harder to justify for one-off projects where BevelUp (free) handles the same operation.
• UV preservation not documented. Mind Sight Studios does not specify how UV texture coordinates behave on bevel faces. Test on textured models before committing to it in a texture-heavy workflow.

Comparison

Which Tool to Use

The decision comes down to what you are rounding and what happens downstream with the model.

• Textured furniture with many edges: BevelUp. UV preservation is the deciding factor — running RoundCorner on a textured cabinet door and checking each bevel face manually is not a viable workflow at scale. BevelUp handles UV projection reconstruction automatically on every rounded edge.
• SketchUp 2017–2021 or models where you need Bevel / Sharp mode: RoundCorner. BevelUp requires 2022+. If you’re on an older version, or if you need the flat chamfer mode or the Sharp edge-reconstruction mode, RoundCorner is the only plugin option.
• Architectural moldings, ogee profiles, any non-arc cross-section: Follow Me. No plugin currently generates custom profiles. If the edge cross-section is anything other than a flat chamfer or a circular arc, you are drawing it with Follow Me.
• Iterative design with geometry changes after beveling: Bevel (Mind Sight Studios). If furniture or products go through multiple revision rounds after beveling — client feedback, parametric resizing, late layout changes — Live Bevel is the only option that does not require a bevel-undo-edit-redo cycle every time. The $49 license pays for itself quickly on complex, revision-heavy projects.
• Models going to CNC: Use Bevel mode (either BevelUp with segments=1, or RoundCorner’s Bevel mode). A flat chamfer creates a single face with a predictable toolpath. A rounded fillet adds faces in proportion to the segment count, which multiplies the polygon count in your CNC layout — relevant if you are exporting DXF panels via ABF and the CAM software has to process the extra faces.

Every plugin in this comparison builds on the same primitive that SketchUp has shipped since version 6: the Follow Me tool. Understanding it is useful context for knowing why plugins exist — and when to bypass them entirely.

Follow Me — The Native Baseline (No Plugin Required)

Follow Me is a core SketchUp tool available in every version since SketchUp 6. It sweeps a 2D profile face along a path, making it the right choice when you want a non-standard bevel profile — a cove, an ogee, a bullnose, or any custom cross-section. Plugins give you a circular arc or a flat chamfer; Follow Me gives you whatever profile you draw.

The standard round-corner workflow with Follow Me:

1. Select the edge you want to round.
2. Draw a perpendicular face at one end of the edge — typically a small square face attached to the corner.
3. On that face, draw the profile arc (arc tool, two clicks for endpoints, one for the arc height). The arc’s bulge toward the interior of the corner will become the rounding geometry.
4. Delete the flat part of the profile face, leaving only the arc face.
5. Select the edge path first (or select the face and let Follow Me infer the path), then apply Follow Me.
6. Delete the original sharp edge and the stub face at the starting end.

This produces the cleanest possible geometry: quads, no triangulation, no hidden stray edges. For architectural moldings, furniture edge profiles (Roman ogee, cove-and-bead), or any case where the cross-section is not a simple arc, Follow Me is the only tool that handles it. No plugin can match it for custom profiles.

Where Follow Me falls short: it is one edge at a time. A dining table with four legs, each needing four edges rounded, requires 16 separate Follow Me operations — or clever use of component instances to apply one operation everywhere at once. BevelUp and RoundCorner handle the entire selection in one pass.

One subtlety: Follow Me does not always close the geometry cleanly at corners where two or more rounded edges meet. At a convex three-edge corner (like the top corner of a box), three separately swept arc faces will leave a small triangular gap or overlap. Plugins handle this corner join automatically. With Follow Me, you often need to manually intersect faces at corners and delete the excess geometry.