Half-life
A half-life in Salesforce is the time-decay rule that lowers an idea's popularity ranking as its supporting votes age.
Definition
A half-life in Salesforce is the time-decay rule that lowers an idea's popularity ranking as its supporting votes age. It is a setting under Setup, Ideas Settings, that controls how quickly older ideas drop on the Popular Ideas subtab so newer ideas with recent votes can surface. The value is entered in days, and it applies across every zone in the org.
The same idea of a half-life also shows up in Salesforce Knowledge, where an article's average rating shifts over time so old votes do not keep a stale article artificially high or low. Both uses share one principle: recent activity should count for more than activity from long ago. The Ideas Half-Life field is the version most admins set by hand, so this entry focuses there and notes the Knowledge behavior alongside it.
How idea half-life shapes the Popular Ideas subtab
Where the Half-Life setting lives
The Half-Life (in days) field sits on the Ideas Settings page in Setup. You reach it by going to Setup, entering Ideas Settings in the Quick Find box, and clicking Edit. The field does not appear until Ideas is enabled and the page has been saved at least once, which trips up admins who expect to see every option on a fresh org. Editing these settings requires the Customize Application permission, so a standard admin profile usually has it but a delegated admin may not. The same page is where you enable Ideas, turn on the HTML editor for posts and comments, switch on the Categories field, and enable Reputation. Several of those toggles are one-way: once Categories or the rich-text editor is on, you cannot turn it back off. Half-Life is different. It is a plain numeric field you can raise or lower at any time, and the change takes effect for ranking going forward. That makes it the safest of the Ideas settings to experiment with, because nothing about the data is destroyed when you adjust it.
The mechanic behind the number
Every idea carries a score. Posting an idea casts an automatic vote worth ten points. Each promote adds ten more, and each demote subtracts ten. A user can promote or demote a given idea only once, and cannot promote an idea they already demoted. If the Popular Ideas subtab simply sorted by that raw score, the oldest ideas with the most accumulated votes would sit at the top permanently. Salesforce avoids that by ranking the Popular Ideas subtab with an internal calculation that reflects the age of an idea's positive votes, not the static point total. Half-life is the dial that sets the pace of that aging. A shorter half-life pushes older ideas down the page faster, clearing room for fresh submissions. A longer half-life lets a well-supported idea hold its position for a longer stretch. The Recent Ideas and Top All-Time views are not affected, because they sort by post date and lifetime score respectively. Half-life only governs the Popular view.
Reading the decay in practice
Picture two ideas that each gathered fifty net points. One earned its votes this week; the other earned the same votes two years ago and has been quiet since. On the Popular Ideas subtab the recent idea ranks higher, because the older idea's contribution to the popularity calculation has faded with time. Set a short half-life and the gap between them widens quickly, so the stale idea slides off the first page within days. Set a long half-life and the two stay closer together for weeks. The decay is gradual rather than a cliff, so an idea does not vanish at any single moment. It simply loses ranking weight steadily. Nothing about this changes the idea's stored score or its visibility elsewhere. The idea still appears in search, on the Recent and All Ideas lists, and on its own detail page. Half-life is purely a sorting influence on one subtab, which is the single most common point of confusion when admins first meet the setting.
Decay is not demotion or archival
Three separate things can push an idea down or out, and mixing them up leads to bad configuration choices. Half-life decay lowers an idea's rank on the Popular subtab over time, but the idea stays fully active. Demotion is a deliberate vote by a member that subtracts ten points from the score, signalling disagreement rather than age. Closing an idea, by moving it to a status such as Merged, Declined, or a custom closed value, is an admin or moderator action that takes the idea out of active consideration. Half-life cannot replace moderation. A zone that never closes resolved or duplicate ideas will still see clutter, because decay slows an idea's climb but does not remove it from the catalog. The healthiest Ideas zones pair a sensible half-life with active status management, so recent ideas rise on their merits while completed or rejected ideas are formally closed out. Treat the half-life as a background tuning knob and status changes as the deliberate housekeeping.
The Knowledge article rating parallel
Salesforce Knowledge applies a comparable time-decay idea to article ratings, though it is not a field you configure. When users rate articles, the average rating reflects recent feedback more than old feedback. If an article stops receiving new votes, its average rating drifts over time rather than freezing at whatever value it once held. The aim matches the Ideas case: stop outdated activity from giving a misleading signal. An article that was rated five stars years ago should not outrank a currently useful article purely on the strength of long-past votes. Because this behavior is built into the rating engine, admins do not set a Knowledge half-life value the way they set the Ideas one. It is worth knowing the parallel exists, since reporting on article ratings can show movement that has no matching new votes, and that movement is the decay at work rather than a data error. When someone on the team asks why a quiet article's rating shifted, the time-decay model is usually the answer.
Choosing a starting value and tuning it
There is no universally correct half-life, because the right number depends on how fast your community posts and votes. A busy public zone with daily submissions benefits from a shorter half-life, so the Popular subtab stays lively and new contributors see their ideas get a fair shot near the top. A quiet internal zone where ideas trickle in monthly does better with a longer half-life, so a good idea does not slide out of view before colleagues have a chance to find it. Pick a starting value, watch the Popular Ideas subtab for a week or two, and adjust based on what you see. If the same handful of ideas hold the top spots for weeks on end, shorten the half-life. If promising new ideas disappear before they gather support, lengthen it. Make small moves rather than large swings, and give each change time to play out before judging it. Document the value you settle on, because half-life is the kind of quiet setting whose purpose is easy to forget months later.
Where Ideas runs and who sees it
Ideas is available in Salesforce Classic and in Experience Cloud sites, so the audience for a half-life setting depends on where you publish the zone. An internal-facing Classic org keeps the conversation among employees, while an Experience Cloud site can open a zone to customers or partners. The half-life applies the same way in both, because it is an org-wide Ideas setting rather than a per-site one. That single scope is important to remember: you cannot give one zone a fast decay and another a slow one through this field alone. If different communities truly need different pacing, that is a structural conversation about how you separate zones and audiences, not something the half-life value resolves. Salesforce also hosts its own public feedback community, the IdeaExchange, which runs on the same family of ideas-and-voting concepts. For most admins, though, the practical surface is their own zone, the Popular Ideas subtab, and the single Half-Life field that quietly governs how that subtab breathes over time.
How to set the Ideas Half-Life in Setup
The Half-Life value is set on the Ideas Settings page in Setup. You need Ideas enabled first and the Customize Application permission. Here is the path and what each related control does.
- Open Ideas Settings
From Setup, type Ideas Settings in the Quick Find box and select it. If Ideas is not enabled yet, enable it and save once so the full set of fields, including Half-Life, appears.
- Click Edit
Select Edit on the Ideas Settings page. Confirm the Enable Ideas box is checked, since the Half-Life field is only relevant when Ideas is active for the org.
- Set the Half-Life (in days) value
Enter the number of days that should govern how fast older ideas lose ranking on the Popular Ideas subtab. A smaller number ages ideas faster; a larger number lets popular ideas hold longer.
- Save and observe
Save the page. Watch the Popular Ideas subtab over the next week or two, then return to this field and adjust up or down based on whether ideas are turning over too fast or too slow.
The number of days controlling how quickly old ideas drop in ranking on the Popular Ideas subtab. Lower values favor recency; higher values favor accumulated support.
Activates Ideas for the org and shows the Ideas tab. The Half-Life field only matters while this is on.
Lets members earn points and ratings for zone activity. It works alongside ranking but is separate from half-life decay.
Turns on multi-select categories for organizing ideas. Note this is a one-way switch and cannot be disabled once enabled.
- The Half-Life field does not appear until Ideas is enabled and the settings page is saved at least once.
- Half-Life is org-wide. Every zone shares the same value; you cannot set different decay rates per zone from this field.
- Changing the value affects ranking only. It never alters an idea's stored score or removes any idea from search and list views.
- Editing Ideas Settings requires the Customize Application permission, which a delegated admin profile may lack.
Trust & references
Cross-checked against the following references.
- Understand and Work with IdeasSalesforce
- Enable and Customize Ideas SettingsSalesforce
Straight from the source - Salesforce's reference material on Half-life.
- Enable and Customize Ideas SettingsSalesforce
- Enable Ideas in Your Experience Cloud SiteSalesforce
Hands-on resources to go deeper on Half-life.
About the Author
Dipojjal Chakrabarti is a B2C Solution Architect with 29 Salesforce certifications and over 13 years in the Salesforce ecosystem. He runs salesforcedictionary.com to help admins, developers, architects, and cert/interview candidates sharpen their fundamentals. More about Dipojjal.
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Q1. What is Half-life in Salesforce scoring contexts?
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