Bug Severity vs Priority
Severity and priority are two different axes that people constantly collapse into one. Severity = how badly it breaks the product (technical impact). Priority = how soon it must be fixed (business urgency). A bug can be high on one axis and low on the other. This sheet is the quick decision aid — the full triage process and report templates are linked below.
The two axes
| Axis | Owned by | Asks | Example values |
|---|---|---|---|
| Severity | QA / Engineering | How much functionality is lost? | S1 Critical · S2 Major · S3 Minor · S4 Cosmetic |
| Priority | Product / PM | How urgently must we fix it? | P1 Urgent · P2 High · P3 Medium · P4 Low |
Severity × Priority matrix
| P1 — Urgent | P2 — High | P3/P4 — Lower | |
|---|---|---|---|
| S1 Critical | Checkout down in prod | Crash behind an unreleased flag | Critical bug in a deprecated feature |
| S2 Major | Login fails for a user segment | Broken CSV export | Edge-case error few users hit |
| S3 Minor | Wrong price shown on pricing page* | Misaligned button on key flow | Minor validation quirk |
| S4 Cosmetic | Typo in the company name on launch day* | Padding off by 2px on hero | Console warning, no user impact |
* Low severity, high priority — these are the ones the single-field model gets wrong: trivial to fix technically, but business-urgent.
When to use
Reach for this during triage, bug write-up, and release sign-off when you're deciding what blocks the release versus what ships to the backlog.
Common mistakes
- Using one field for both — losing the "cosmetic but urgent" and "critical but can wait" cases.
- Letting the reporter set priority; priority is a business call, severity is a QA/Eng call.
- Inflating severity to force a fix (use priority for urgency instead).
- No agreed scale — define S1–S4 / P1–P4 once and put it in the bug template.
Evidence to capture
Repro steps, environment, the user/segment impacted, frequency, and a screenshot or log. Severity follows from impact + frequency; priority follows from who's affected and when.
// Related resources