Hidden fields carry data through a form invisibly: campaign tags, referrer paths, or identifiers passed in the URL. Respondents never see them, yet every submission arrives tagged with where it came from, which makes attribution possible without cookies, scripts, or extra questions.
Why attribution breaks on most forms
Marketing knows the ad click worked, sales sees only an anonymous email. The connection lives in the landing URL, and unless something captures those parameters, the context evaporates between click and submission. Hidden fields are that something.
Setting up capture
- 1
Add hidden fields
Drop hidden fields onto the form for each parameter worth keeping, commonly utm_source, utm_campaign, utm_medium, plus your own identifiers like promo codes.
- 2
Read values from the URL
Configure each field to pull its value from matching query parameters, so a landing link ending in utm_source=newsletter fills that value silently.
- 3
Provide safe defaults
Set fallback values such as direct for traffic arriving without tags, so reports distinguish tagged campaigns from untagged visits.
- 4
Send the data onward
Reference hidden fields in notification email subjects, sheet columns, and webhook payloads. Attribution then travels with every submission automatically.
Uses beyond marketing
- Pre-fill employee IDs on internal request forms linked from your intranet.
- Attach ticket numbers to feedback forms embedded inside your product.
- Track which QR code poster drove event signups by varying one parameter.
- Carry session context into multi-step processes so handoffs stay intact.
Templates to start from
Frequently asked questions
- Do hidden fields work with embedded forms?
- Yes. Parameters placed on the embed URL behave the same as direct links, so iframe or script embeds can receive campaign context. Values persist through the submission and appear in exports exactly as they would on hosted pages.
- Can respondents see or change hidden field values?
- Values stay invisible in the rendered form, so respondents neither notice nor edit them during filling. Anyone inspecting network traffic could spot them, which is why sensitive data belongs server-side; campaign tags and identifiers are ideal uses.
- Which parameters should every form capture?
- At minimum utm_source, utm_medium, and utm_campaign, since together they explain which channel and promotion produced each lead. Add gclid or fbclid when paid search and social matter, and always include one business-specific code for offline tracking.
Put this to work on a real form
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