Make a form change while someone is filling it in, based on what they answer.
Without conditional logic, every respondent sees exactly the same questions in exactly the same order, no matter what they answer. Conditional logic lets a form behave more like a conversation — if someone says they don't have a car, you don't then ask what color it is.
The two ways a form can changeCopied!
Show or hide a questionCopied!
A question appears or disappears on the same page, depending on an earlier answer. Nobody ever sees both versions, and they don't know the other one exists.
Skip a whole pageCopied!
In Furmbase, a section is a page — everything after a section becomes a new page with its own Next button. Conditional logic lets a page send respondents somewhere else entirely, so a speaker can jump straight to the speaker questions and never see the attendee pages.
Charging different pricesCopied!
Because a Payment question can be hidden or shown like any other question, the price a respondent is asked for can depend on their own answers — a student rate and a public rate on the same form and the same link, for example. The price is always worked out on Furmbase's own server from the form as it's saved, never from the respondent's browser — see Payment Collection. This works even across currencies: a form may hold an NGN branch and a USD branch, as long as no single respondent can reach both.
How to use itCopied!
Setting up a show/hide ruleCopied!
Open your form in the builder and find the question you want to show only sometimes
On that question card, click the ⋯ menu → Conditional logic
A panel opens, reading like a sentence: Show this question when every rule matches — If [ an earlier question ] [ is ] [ a value ]
Click Add another rule if one condition isn't enough — each row is labeled and / or so you can see how they combine
Choose every rule matches (all must be true) or any rule matches (one is enough)
Click Done — or flip Show to Hide if that reads more naturally
Tip
At the bottom of the panel, Furmbase writes your rule out as a plain sentence — “Show ‘Which school?’ when ‘Are you a student?’ is ‘Yes’.” Read that line before you publish; dropdowns are easy to misread, a sentence usually isn't.
A question with no rules shows nothing extra on its card. Once a question has rules, a green branch icon appears next to duplicate and delete — click it to open or close the rules, and scanning down a long form, the green icons are exactly the questions that branch. Duplicating a question keeps its rules; editing the copy's rules never touches the original.
Send people to a different pageCopied!
Add a section wherever you want a new page to begin
On that section card, click the ⋯ menu → Add conditional rules
Add a rule: If all match [ an earlier question ] [ is ] [ a value ] then [ go to page N ]
Add as many rules as needed — they're checked top to bottom, and the first one that matches wins
Set the Otherwise line for what happens when nothing matches: continue to next page, submit the form, or go to page X
Click Done
Note
Sections have no branch icon — routing is their version of the same feature, and it lives in the ⋯ menu. Once a section has rules, the menu entry reads Edit conditional rules with a tick beside it.
The rule that keeps things saneCopied!
You can only build a rule on a question that comes ABOVE the current one — the question picker only lists earlier questions. A rule needs an answer the respondent has already given, so a question can't depend on an answer from further down the form that hasn't been answered yet.
Things Furmbase handles for youCopied!
A hidden question never blocks Submit — if it's marked required but hidden for a respondent, it isn't required for them
Answers from an abandoned path are thrown away — if someone answers, backtracks, and takes a different branch, the abandoned answer is never saved with their response
Back goes where they actually came from — jumping from page 1 to page 4 means Back returns to page 1, not a page they never saw
A broken rule never strands a respondent — if you delete a page a rule pointed at, respondents simply continue to the next page; you get the warning instead, in the builder
Warnings in the builderCopied!
While you build, Furmbase checks your logic and shows problems above the questions.
Red — must fix before publishing
What it means
Rule points at a deleted question
You removed a question another rule depended on
Rule depends on a later question
The rule uses an answer that hasn't been given yet
Rule depends on itself
A question can't decide its own visibility
Yellow — worth checking, still publishable
What it means
Page cannot be reached
No combination of answers leads there — nobody will see it
Unreachable required questions
That page has required questions nobody will ever answer
Note
You can always save a draft with these problems, so you never lose work mid-edit — you just can't publish until the red ones are fixed.
Which questions can drive a ruleCopied!
Question type
Can drive a rule?
Multiple choice, Dropdown, Checkboxes
Yes
Linear scale, Rating
Yes
Short answer, Paragraph
Yes
Date, Time
Yes
File upload
Partly — only whether a file was uploaded
Payment
No — whether someone paid is only known after they submit
Title, Section, Image, Video
No — these are layout, not questions
Limits and notesCopied!
Pages can loop — you can send people back to an earlier page. The builder warns about a loop with no way out, but doesn't stop you, since sometimes a loop is what you want
Rules use option IDs, not the option's text — renaming an option from “Yes” to “Yeah” doesn't break a rule that points at it. Deleting an option and adding a new one does, and the builder will flag it
Existing forms are unaffected — a form with no rules behaves exactly as it did before
Warning
Rules are checked in the order they're listed, and the first match wins. If two rules could both apply, reorder them if the outcome looks wrong.
