Custom Input Fields
Collect any data you need with campaigns beyond first name and email address.
Custom Input Fields is an OptiMonk feature that lets you add any type of data collection field to your campaigns beyond the standard email address and first name inputs. Every piece of additional information a visitor shares at opt-in — their phone number, date of birth, website URL, a free-text answer, a radio button selection, or any other custom property — is captured by OptiMonk and passed to your connected email platform, CRM, or Shopify customer record via field mapping. Available field types include text (single-line), text area (multi-line open-ended answer), email, phone number, number, date, URL, and radio buttons — covering structured data collection, preference capture, feedback gathering, and contact enrichment in a single form element. Fields are added directly in OptiMonk's campaign editor, can be marked as required or optional, and are fully styleable to match your campaign design. Custom Input Fields work together with multi-step campaigns: you can collect an email address on the first page to lower the initial conversion friction, then ask for additional details — birthday, phone, preferences — on the second page, where visitors who have already committed to the opt-in are more willing to share further information.
Key benefits
- Collect first-party data at the moment of highest engagement. A visitor filling out an OptiMonk popup has already decided to engage — making it the highest-quality moment to ask for additional information. Custom Input Fields let you capture phone numbers for SMS marketing, birthdays for personalized anniversary offers, website URLs for B2B qualification, or open-ended feedback about purchase experience — all within the same campaign that captures the email address, without requiring a separate form or survey tool.
- Every custom field maps directly to your ESP or CRM. Data collected in custom fields is not siloed inside OptiMonk. Through OptiMonk's integration field mapping, each custom field can be connected to a corresponding field in your email platform or CRM — so a "date of birth" field in your popup populates the birthday field in Klaviyo, a "phone number" field populates the SMS opt-in field in Attentive, and a "preference" radio button populates a custom property in HubSpot. The enrichment happens automatically at the moment of submission.
- Multi-step forms reduce friction while maximizing data collected. Asking for six fields in a single popup form is a proven conversion killer. Custom Input Fields are designed to work across multi-step campaigns: collect just the email on step one (maximizing opt-in rate), then present one or two additional fields on step two (capturing enrichment data from visitors who have already committed). This sequential approach consistently yields more data per subscriber than single-page forms with the same number of fields.
How it works
In the OptiMonk campaign editor, click Add element and drag an Input field block into your campaign layout. From the element settings, select the field type — email, text, phone number, number, date, URL, text area, or radio buttons. Set a label for the field (visible to the visitor), mark it as required or optional, and add placeholder text to guide the visitor on what to enter.
Give the custom field an internal name that identifies it in your OptiMonk database and in the field mapping interface — for example, "birthday" or "phone_number" or "preference_category." Configure display settings independently for desktop and mobile if needed, adjusting font size, padding, and layout to fit both views. For radio button fields, define the answer options the visitor will see.
After finishing the campaign design, navigate to the integration section and select your connected email platform or CRM. In the field mapping interface, find your custom field by its internal name under OptiMonk input fields, and connect it to the corresponding field in your destination platform. Save and publish — every submission will automatically route each field's value to the correct property in your marketing stack.
Frequently asked questions
What are Custom Input Fields in OptiMonk?+
Custom Input Fields are form elements you add to OptiMonk campaigns to collect data beyond the standard email and first name. Available types include text, text area (open-ended), email, phone number, number, date, URL, and radio buttons. Each field is added in the campaign editor, can be required or optional, and maps directly to your connected email platform or CRM via OptiMonk's field mapping integration so the data flows automatically to the right property on submission.
What types of input fields are available?+
OptiMonk supports the following field types: email address, text (single-line free text), text area (multi-line open-ended response), phone number, number, date (with configurable format), URL, and radio buttons (multiple-choice with predefined options). This covers the full range of structured data collection needs — from contact detail enrichment and preference capture to qualitative feedback and birthday collection.
Can I make a custom field required?+
Yes. Each input field in the editor can be set as required or optional independently. Required fields must be filled in before the visitor can submit the form — OptiMonk will prevent submission and highlight the empty required field if the visitor tries to proceed without completing it. This is useful for fields critical to your segmentation logic, such as a phone number for an SMS opt-in campaign.
How does data from custom fields get to my email platform or CRM?+
Through OptiMonk's integration field mapping. After setting up a custom field in the campaign editor and connecting your email platform or CRM in the integration settings, you map each OptiMonk input field to the corresponding property in the destination system. When a visitor submits the campaign, OptiMonk transfers each field's value to the mapped property automatically — in real time, without any manual export or import step.
Can I use custom fields in multi-step campaigns?+
Yes, and this is one of the most effective ways to use them. In a multi-step campaign, you place the email field on the first page to capture the opt-in with minimal friction, then add custom fields — such as phone number, birthday, or preference question — on the second page. Visitors who have already opted in on page one are significantly more likely to fill in the additional fields on page two, resulting in higher enrichment rates without sacrificing the initial opt-in conversion rate.
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