Severity HighPriority High
- Checkout fails with a 500 error for all card payments
- Users can see other customers' order history
- App crashes on launch on the most-used Android version
QA Documentation
Bug Severity and Priority Reference
Definitions, real examples and a 4-question severity/priority helper.
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Decision helper
Suggestion
- Severity
- Major
- Priority
- P2 High
Why
- A partially broken feature starts at Major.
- Customer-visible problems are scheduled for the current release.
These rules give a consistent starting point. Your team’s definitions and the triage owner have the final say; priority in particular depends on business context this helper cannot see.
Severity vs priority: the 2 × 2
Severity is the technical impact on the system. Priority is how soon the business needs it fixed. They are set independently, often by different people (QA proposes severity; the product owner decides priority).
Severity HighPriority Low
- Report export crashes the app, but only on a legacy browser used by 0.1% of users
- Data corruption in a feature behind a disabled feature flag
- Crash when importing a 2 GB file when the documented limit is 50 MB
Severity LowPriority High
- Company name misspelled in the homepage header
- Wrong price shown in a launch-day marketing banner (checkout charges correctly)
- Partner logo missing on a page required by a contract
Severity LowPriority Low
- Tooltip text misaligned by a few pixels in an admin settings page
- Inconsistent capitalisation in a rarely used dialog
- Footer link hover colour differs from the design
Severity levels
| Level | Definition and example |
|---|---|
| Blocker | Stops testing or use of the product entirely: crash on start, cannot sign in, build not deployable. No workaround.e.g. App crashes on launch; sign-in returns HTTP 500 for every user. |
| Critical | A core function fails, data is lost or corrupted, or there is a security/privacy breach. No acceptable workaround.e.g. Customers are charged twice; one user can read another user’s invoices. |
| Major | A significant function does not work as specified, but there is a workaround or the impact is limited to part of the feature.e.g. Search ignores the date filter; export fails over 10 MB but smaller exports work. |
| Minor | Behaviour is wrong but the function is usable: unclear error message, wrong default, layout problem that does not hide content.e.g. Error says “Invalid input” without naming the field; wrong default sort order. |
| Trivial | Cosmetic issue with no functional impact: spacing, alignment, minor wording in rarely seen places.e.g. A settings dialog button is 2px out of alignment. |
Priority levels
| Level | Meaning |
|---|---|
| P1 Highest | Fix now. Hotfix or blocks the release; someone starts on it today. |
| P2 High | Fix in the current sprint/release before shipping. |
| P3 Medium | Fix in a planned upcoming release. |
| P4 Low | Fix when convenient; may be batched or deferred to the backlog. |
Jira’s default priorities (Highest, High, Medium, Low, Lowest) map naturally onto P1–P4 with Lowest as a backlog bucket. Names vary between teams; agree on definitions, not just labels.
Common mistakes
- Setting priority equal to severity by default. Severity describes impact on the system; priority is a business scheduling decision. They are often different.
- Inflating severity to get a bug fixed sooner. It erodes trust in triage; argue for priority instead, with the business reason.
- Rating a crash as Critical without checking reach. A crash in an unreachable code path is still high severity, but rarely high priority.
- Treating all cosmetic issues as Trivial. A broken layout that hides the Buy button is a functional problem.
- Never revisiting priority. A Low-priority bug can become urgent when a customer escalates or a launch date approaches.
- Leaving security and data-loss bugs at default severity. These are at least Critical until someone with context downgrades them.
About this tool
Arguments in bug triage usually come from mixing up two questions. Severity is how badly the bug affects the product; priority is how soon the business needs it fixed. A typo in the company name on the homepage is low severity but high priority, while a crash in a report only reachable from an unsupported browser can be high severity and low priority. This page gives definitions for five severity and four priority levels with an example for each, the classic 2×2 with real-world cases, and the mistakes that cause the most friction. The decision helper asks four questions about impact, workaround, reach and business visibility, then suggests a severity and priority and explains each step of the reasoning, so you can use it to calibrate a team rather than to replace judgement.
How to use it
- Answer the four questions about the bug: impact, workaround, how many users and business visibility.
- Read the suggested severity and priority and the reasoning behind them.
- Compare with the 2×2 examples and the level definitions, then copy the suggestion into your ticket.
Bug Severity and Priority Reference FAQ
Who sets severity and who sets priority?
Commonly the tester proposes severity because it describes technical impact, and the product owner or triage lead sets priority because it depends on business context, release dates and customer commitments.
Can severity change after the bug is reported?
Yes. If investigation shows data loss, a security impact or a much wider reach than first thought, raise it. If a workaround is found, it can come down. Record why in a comment.
Do these levels match Jira?
Jira’s default priority field uses Highest, High, Medium, Low and Lowest; severity is usually a custom field. The names here are common conventions. What matters is that your team writes down its definitions and applies them consistently.