All services08 / 19

Webflow custom code development

Calculators, filters, multi-step forms and maps: the parts of a site that Webflow does not build on its own.

A PAGE WITH EMBED B CODE yoursite.com/moving-quote Get a moving quote CUSTOM CODE, EMBED Quote calculator STEP 1 OF 2 ROOMS 3 1 2 3 4 5 6 7 8 DISTANCE 42 km 0 20 40 60 80 100 Packing service + EUR 210 Piano or safe + EUR 180 Storage, one month + EUR 90 ESTIMATE EUR 1,240 BASE 400 3 ROOMS × 140 420 42 KM × 5 210 PACKING 210 Send me the quote NEXT: CONTACT DETAILS calculator.js consent.js 1 const RATES = { base: 400, room: 140, km: 5, packing: 210 }; 2 3 export function estimate({ rooms, km, packing }) { 4 return RATES.base + rooms * RATES.room 5 + km * RATES.km + (packing ? RATES.packing : 0); 6 } 7 8 form.addEventListener('submit', async (event) => { 9 event.preventDefault(); 10 const lead = collect(form); 11 if (consent.analytics) track('quote_requested', lead); 12 await hubspot.createDeal(lead); 13 showThanks(); 14 }); EMBED LEAD SENT TO HUBSPOT HUBSPOT Deal created, EUR 1,240 ANALYTICS quote_requested CONSENT Analytics granted EMAIL Quote sent to the client COOKIE CONSENT Accept all Reject Settings 10:42:03 quote_requested 10:42:04 hubspot.deal.created
Fig. 2.6A custom calculator embedded in a Webflow page

You might be here because

What you get

The parts of the site that Webflow cannot do on its own.

Written in plain JavaScript where possible, loaded only on the pages that need it, and described so the next developer can read it.

  • Calculators

    Price estimates and configurators that show a number before the visitor has to ask.

  • Multi-step forms

    Quote and booking forms that ask one thing at a time and send clean data.

  • Filters and search

    For CMS lists that have outgrown a single page.

  • Maps

    Interactive maps that read their points from the CMS.

  • Code components

    Small components written in code that sit in the Designer like any other element.

  • Notes for the next developer

    Where the code lives, what it depends on, and how to change it.

How it goes

  1. 01

    Describe what it should do

    In your own words, or with a link to something similar.

  2. 02

    Get an estimate

    In hours, before I start.

  3. 03

    Test on staging

    On a phone and on a slow connection, not only on my screen.

  4. 04

    It goes live, with notes

    A short description of where the code lives and how to change it.

Price

Billed by the hour, with the estimate first.

The estimate covers testing and the notes, not only writing the code.

Hourly rate

40

USD an hour

Shown in

AI customer service platform

Welyo

A mega menu and animated graphics in two languages.

View case
The Welyo home page

Non-profit, urban mobility

Zero Wait

An interactive crossing map for a road-safety campaign.

View case
The Zero Wait home page

Moving company

Minute Men Movers

A site where every screen leads to a quote or a call.

View case
The Minute Men Movers home page

Questions

Does Webflow allow custom code?

Yes, on paid site plans: in the site settings, per page, and in embeds. Longer scripts are kept in a file outside Webflow and loaded from there.

Will custom code slow the site down?

It should not. Scripts load only on the pages that use them, after the page is usable.

Will it break when Webflow updates?

It can, if it leans on Webflow’s internal markup. I attach code to your own classes and attributes instead.

Can you fix code another developer wrote?

Usually yes. I read it first and tell you whether fixing or rewriting is cheaper.

Goes well with

Integrations

Your Webflow site connected to the tools the company already runs on: forms into the CRM, analytics that measures the right things, and consent that holds tags back.

Service

Animation and interactions

Scroll effects, transitions and motion that explains the product, built with GSAP and Webflow Interactions, and tested on phones.

Service

Your site

Not sure what your site needs first?

Get a free site audit

Next service

Language versions

09 / 19

Free audit

Get a free audit of your site.

A 5 to 10 minute recording with three things to fix. No call needed, and nothing to sign afterwards.