Windows desktop · v0.3.0 Browser demo — no install

Wire harness design
that stays out of your way.

LoomFlow is a schematic-first harness editor. Drag to connect — the BOM, cut list, pinouts and drawing sheets derive themselves. It runs offline, stores your work in one portable file, and syncs to the cloud when you want it.

Try in browser Download for Windows

Free for small designs · no credit card

1,600+connectors

56manufacturers

680+contacts, seals & plugs

100%offline-capable

Why LoomFlow

The schematic is the source of truth.
Everything else is derived.

Edit connections the way you think about them — every table, drawing and report updates itself. No hunting through forms to change one wire.

Drag. Connect. Done.

Connectors are nodes, cavities are pins, wires are a drag away. Group wires into signals, twist pairs, add shields and inline splices — edits stay fluid because the design is connections, not spreadsheet rows.

A real parts library, built in.

Deutsch, TE, Molex, Amphenol, Aptiv, JST and 50 more — with mating faces, contacts, seals, cavity plugs and current ratings. Search it, place a part, and the pinout and BOM come pre-filled.

Drawings that draw themselves.

One click exports print-style technical drawing sheets — whole layout or per-harness — plus BOM, cut list and per-connector pinouts. PDF, SVG and CSV, straight from the schematic.

Checks an EE would actually run.

Per-cavity ampacity from contact and wire gauge, bundle derating by conductor count, one-way voltage drop, crimp-range warnings and duplicate-pin validation — flagged live while you edit, not in a report you forgot to run.

One file. Offline. Yours.

A whole harness is a single, self-contained .loomflow file — connectors, layout, device images and all — saved right on your disk. Design fully offline with no account. Turn on cloud sync to share a link and pick up the same file from any machine.

From schematic to shop floor.

Lay out enclosures and PCBs your connectors mount to, and LoomFlow auto-detects isolated bundles into nameable harness groups — each with its own drawing sheet and grouped cut list for the bench.

How it compares

Offline like a CLI. Fluid like a canvas.

LoomFlow exists because nothing else combined a direct-manipulation editor with files you actually own.

	LoomFlow	RapidHarness	harness.design	WireViz
Works fully offline	✓	✓	— browser-based	✓
Drag-to-connect schematic canvas	✓	— form-driven	✓	— YAML input
Single portable project file	✓ images bundled	—	—	— YAML + assets
Built-in manufacturer library	✓ 1,600+ connectors	✓	✓	— define your own
BOM · cut list · drawing sheets	✓	✓	✓	◐ BOM + diagram
Ampacity & voltage-drop checks	✓	◐	◐	—
Free to use	✓ free tier	— trial	◐ limited	✓ open source

Based on publicly available information, July 2026. Corrections welcome.

Built for engineers, by engineers

We don't just make the tool.
We build harnesses with it.

LoomFlow started on a Formula SAE team, built by an electrical engineering student who spends race season crimping Deutsch pins and pulling loom through a chassis at 2 a.m. before a comp. It exists because every other tool got in the way of the build.

So every feature earns its place on a real car first. Cut lists come off LoomFlow and onto the bench. Pinouts get taped to the loom. Drawing sheets go up on the shop wall. If a feature doesn't survive a build weekend, it doesn't ship — and the ones that do were fixed the same night we hit the wall.

On the car

Every release is drawn, printed and wired into a competition harness before it goes out.

On the bench

Cut lists, pinouts and BOMs get used exactly the way you'd use them — because we do.

By the deadline

Missing part or workflow? It gets found at the track and lands in days, not quarters.

— Built trackside, on an FSAE electrical bench.

Feature requests

Missing something?
Ask — it ships fast.

LoomFlow is built in tight loops with the people using it. No roadmap committee, no ticket purgatory: good requests go straight into the queue, and new features deploy in days, not quarters.

Shipped recently