# Tribby3d alternative: StructLoads compared

> Looking for a Tribby3d alternative for tributary areas and load takedown? StructLoads is a free, browser-based option. Here is an honest comparison of the two.

**Category:** Workflow & tools  
**Author:** Elena Marchetti (Structural engineer · Founder)  
**Published:** 2026-05-28

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If you are looking for a Tribby3d alternative for tributary areas and gravity load takedown, StructLoads is a free, browser-based option. Both tools partition a floor into tributary areas for columns and walls; StructLoads adds one and two way framing, ASCE 7 and Eurocode load combinations, and PDF, Excel and CSV exports, with nothing to install and no licence to manage. This page compares the two honestly so you can pick by the job.

## What both tools do

The shared core is tributary analysis: taking a floor and working out how much of its [load](https://en.wikipedia.org/wiki/Structural_load) each support carries. The concept is tool-independent; even [SkyCiv's tributary area tutorial](https://skyciv.com/docs/tutorials/load-tutorials/tributary-area-explained/) defines it the same way, as the area a member is responsible for carrying, extending halfway to the neighbouring supports in each direction, so any tool in this category is automating the identical partition. That is the slow, error-prone step when done by hand, so a tool that computes it exactly saves real time on irregular plans. Tribby3d is a dedicated, paid tool built around this task. StructLoads does the same partition and then continues the gravity takedown all the way to the foundation.

## StructLoads vs Tribby3d at a glance

The verdict column is for a fast, preliminary gravity takedown, not for every structural task.

| Tool | Tributary areas | Takedown + codes | Cost | Verdict |
| --- | --- | --- | --- | --- |
| StructLoads | Columns and walls, one and two way | Multi-level, ASCE 7 and Eurocode | Free, browser | Best for a fast free check |
| Tribby3d | Columns and walls | Dedicated tributary focus | Paid | Good for a paid dedicated tool |
| Spreadsheet | Manual formulas | Manual | Free | Flexible but slow and error prone |

On a clean grid the answers agree; the practical differences are cost, install, and how each handles irregular plans and the steps after the tributary areas.

## Where StructLoads fits

StructLoads is the right pick when you want a quick, free, browser check: draw the plan or import it, place supports, and read tributary areas and factored reactions, then export. There is no licence, which removes the friction of a paid tool for occasional or student use, and the workflow is the one described in [how to do a load takedown fast](/blogs/how-to-do-a-load-takedown-fast-and-check-it). You can start from the [free tributary area calculator](/blogs/free-tributary-area-calculator).

## Where a paid or full tool fits

A dedicated paid tool suits a team that wants a supported, documented tributary workflow and is happy to license it. For complete building design, with member capacity, deflection and lateral loads, you move past any tributary tool to full analysis software such as [SkyCiv](https://skyciv.com/) or a documented calculation platform such as [ClearCalcs](https://clearcalcs.com/). The broader landscape is covered in [best load takedown software](/blogs/best-load-takedown-software).

## Key takeaways: choosing a Tribby3d alternative

For a free, browser-based tributary area and gravity takedown, StructLoads is a strong alternative: same core job, plus multi-level takedown, two codes and exports, with no licence. A paid dedicated tool or a full analysis suite is the better fit for documented team workflows or complete design. Either way the takedown is preliminary, and a qualified engineer signs off the final design.

## Quick answers

### What is a good Tribby3d alternative?
StructLoads is a free, browser-based alternative for tributary areas and gravity load takedown. It computes tributary areas for columns and walls, models one and two way framing, applies ASCE 7 and Eurocode combinations, and exports PDF, Excel and CSV, with no install or licence. For a paid dedicated workflow you might also compare calculation platforms, but for a fast free check StructLoads fits.

### Is StructLoads free?
Yes. StructLoads runs free in the browser: draw the floor, place columns, walls and beams, read the tributary areas and reactions, then export a report. It is built for preliminary analysis and learning. There is no download and no licence to manage, which is the main practical difference from a paid desktop or subscription tool.

### What does StructLoads do that a tributary tool does?
It does the same core job, partitioning the floor into tributary areas for each support, and continues into a full gravity load takedown: accumulating loads down multiple levels, applying code load combinations, and reporting the factored reaction at each column, wall and footing. It also imports plans from DXF and PDF and exports the result.

### Is a free alternative good enough for real work?
For preliminary gravity analysis, column sizing and learning, a free geometric tool is good enough, because the tributary geometry is computed exactly, not estimated. It is not enough for full member design, deflection, or lateral wind and seismic effects, which need full analysis software. A qualified engineer reviews the result before it drives a final design either way.