harness.design has one of the best free plans for drawing harnesses. The alternatives worth a look are Zorowire (free up to 150 connections, cut-length allowances, quotes from labour), Splice CAD (free, 50 web harnesses, strong exports, no 1:1 board in our test), Wiring Studio (from $29 a month, tiled 1:1 PDF documented) and Rapid Harness (Windows, full document set, from $219 a month).
harness.design launched fully in April 2026 and sets a high bar for free tools: unlimited harnesses up to 100 connections, a 1:1 formboard printed as tiled panels on office paper, BOM and wiring-table exports, and apps for macOS and Windows next to the browser. In our test its A4 panels printed exactly to scale. We found no public complaints about it. The reasons to look further are about what a shop needs after the drawing.
Where harness.design stops
- Cut lengths. In our test harness the cut lengths were the bare bundle sums — no allowance for the terminal, the splice or rounding, and no setting for them. No strip lengths were found.
- No quote. Material prices add up; there is no labour, setup, quantity break or margin.
- Excel import through an AI assistant. The documented route for Excel files is an MCP-capable assistant, not a fixed importer (docs).
- The 101st connection and the first revision. Free stops at 100 connections per harness and cannot create revisions; Pro is $29 a seat a month, or $24 billed yearly (pricing).
- Tiles without overlap or marks. The panels join edge to edge; registration marks are not documented.
The alternatives at a glance
| Tool | Cheapest paid, as listed | Free plan | Platform | 1:1 formboard | Quote from labour |
|---|---|---|---|---|---|
| Zorowire | Starter €24 a month; Shop €79 a month for 5 users | Unlimited harnesses × 150 connections, 3 quotes a month | Browser (macOS, Windows, Linux) | Yes; tiled with marks and a check ruler, or one piece | Yes: labour from operations, setup, breaks, margin, customer PDF |
| harness.design | $29 per seat a month; $24 billed yearly | Unlimited harnesses × 100 connections | Browser, macOS and Windows apps | Yes, tiled panels | None found |
| Splice CAD | No paid plan yet | 50 harnesses on the web | Browser and desktop | No 1:1 formboard in our test | None |
| Wiring Studio | Lite $29 a month; Pro $99; Team $79 per seat (2 minimum) | Free plan with small project and component caps | Browser and desktop | Tiled 1:1 PDF documented; the export hung in our test | Price × quantity × one markup; no labour |
| Rapid Harness | $219 a month per user (Standard) | 5 designs × 30 connections | Windows desktop | Yes, every plan | None found |
| WireViz / Filare | Free (GPL-3.0) | Everything | Python command line | No | No |
Which one fits
- Keep drawing for free, add production data: Zorowire's Free plan has 150 connections, two revisions kept, cut lengths with your allowances, strip lengths and terminals per end, and 3 quotes a month.
- Lots of exports, free: Splice CAD exports cut lists, BOMs and WireViz files; in our test its drawings were fitted to the page, not 1:1.
- Allowances at branch points: Wiring Studio applies an allowance per wire end and per branch point; its tiled export did not finish in our tests.
- Windows and a full document set: Rapid Harness, from $219 a month per user.
Bringing harness.design files to Zorowire
The .harness format is openly licensed and documented, so Zorowire reads it directly: connectors, wires, cables, splices and bundle lengths come across, and anything that cannot be represented is listed as a finding. Then set your allowances and the cut list follows. The full comparison is on Zorowire vs harness.design.
Start free
Start freeFrequently asked questions
Is harness.design free?
Yes, for unlimited harnesses up to 100 connections each, without creating revisions. Pro, with unlimited connections, revisions and team seats, costs $29 per seat a month or $24 billed yearly (checked 30 October 2026).
Does harness.design add terminal allowances to cut lengths?
Not in our test on 30 October 2026: cut lengths equalled the bundle sums and we found no allowance setting. Zorowire adds connector and splice allowances, loops, slack and rounding by shop settings.
Can I import my harness.design projects into Zorowire?
Yes. Zorowire imports .harness files, including bundle lengths.
Which free harness tool prints a 1:1 formboard?
harness.design (tiled panels) and Zorowire (tiled with overlap, registration marks and a check ruler, or one piece) both do on their free plans. Rapid Harness Free does too, limited to 30 connections per harness.
Sources
- harness.design, homepage and pricing section · retrieved 2026-10-30
- harness.design docs, FAQ (Free limits, platforms, offline) · retrieved 2026-10-30
- harness.design docs, Formboard mode and panels · retrieved 2026-10-30
- Zorowire hands-on test of harness.design (Free plan, fixture F2) — Zorowire test or research, 2026-10-30
- Splice CAD, Pricing (Free: 50 harnesses on the web) · retrieved 2026-10-30
- Zorowire hands-on test of Splice CAD, web app (fixture F2) — Zorowire test or research, 2026-10-31
- Wiring Studio, homepage and plans (Free, Lite $29, Pro $99, Team $79 per seat) · retrieved 2026-10-30
- Zorowire hands-on test of Wiring Studio, web and desktop (fixture F2) — Zorowire test or research, 2026-10-31
- Rapid Harness, Pricing · retrieved 2026-10-30
- Rapid Harness, homepage (features, Windows desktop app) · retrieved 2026-10-30
- Rapid Harness, version history · retrieved 2026-10-30
- WireViz on GitHub (GPL-3.0, latest release v0.4.1 of 2024-07-13) · retrieved 2026-10-30
- harness.design docs, Excel import through an AI assistant (MCP) · retrieved 2026-10-30
- harness.design docs, Revisions · retrieved 2026-10-30
