Tri-Inspector
Free inspector attributes for Unity [Custom Editor, Custom Inspector, Inspector Attributes, Attribute Extensions]
The Lens
By Erik Loyd, SaaS CEO and former COO/CFO of an AWS Premier Partner.
Updated Sep 2026
Tri Inspector makes Unity's inspector usable without paying for Odin. Add attributes to your fields and you get grouped and tabbed layouts, validation with inline error messages, conditional show and hide, buttons that call methods from the inspector, read-only fields, info boxes and reorderable table lists. It is the same category of quality-of-life work that makes designers stop asking engineers to change values for them. MIT licensed, distributed through OpenUPM.
Nothing to run. Install the package from OpenUPM or a git URL and the attributes work. Version 2.0 is a preview release rebuilt on Unity's UI Toolkit, requiring Unity 6 or newer, with proper prefab override support so modified properties highlight, revert and apply correctly across prefab instances and variants. TableList rows are now drag-reorderable. If you need stability today, the 1.x branch is still there and still maintained.
Free with no paid tier, which is the entire pitch given Odin Inspector sells for $55 per seat. Tri Inspector also integrates with Odin and Odin Validator rather than fighting them, so adopting it does not burn a bridge. Solo developers and small studios get most of Odin's daily value for nothing.
The catch is that 2.0 is explicitly flagged as preview and may contain bugs, and it drops everything before Unity 6. Odin still wins on breadth, serialization of types Unity will not touch, and a support contract. Free covers the common cases, not all of them.
Free vs Self-Hosted vs Paid
fully freeFree (Open Source)
- MIT licensed, installed via OpenUPM (
com.codewriter.triinspector) or a git URL - Inspector attributes for grouping, tabs, validation, conditional display, buttons, read-only fields, info boxes and decorators
- Reorderable TableList, styled lists and groups
- 2.0 preview rebuilt on UI Toolkit with full prefab override support, requires Unity 6+
- Stable 1.x branch maintained for older Unity versions
- Integrates with Odin Inspector and Odin Validator rather than replacing them
Paid
None from this project. The commercial comparison is Odin Inspector on the Unity Asset Store at roughly $55 per seat, which adds broader attribute coverage, custom serialization of types Unity does not serialize natively, and vendor support.
Self-Hosted Costs
$0. It is an editor-only Unity package. No runtime cost, no build size impact, no services.
When to Pay
Pay for Odin when you need serialization of dictionaries, interfaces and generics that Unity refuses to handle, or when you want a vendor to call. For inspector layout and validation alone, Tri Inspector covers it at no cost.
Completely free and open source under MIT. It covers most of what studios buy Odin Inspector for at roughly $55 per seat.
What to do by team size
- Solo
- free; most of Odin's daily value at no cost
- Small team
- free; pin to the 1.x branch if you are not on Unity 6 yet
- Medium team
- free, though Odin's serialization may still justify the seat cost
- Large team
- free for layout and validation; buy Odin where custom serialization is load-bearing
Get tools like this every Wednesday
One featured tool, three on the radar. No fluff.
A low score is not a verdict on quality. Young and niche tools start low by design. How we calculate scores
Trust Signals
License: MIT License
Use freely, including commercial. Just keep the license.
Commercial use: ✓ Yes
About
- Owner
- CodeWriter Packages (Organization)
- Stars
- 1,431
- Forks
- 90