Heading Level h1–h6 Order Sequence Check
Finds adjacent upward jumps greater than one in supplied heading levels. Returns zero-based positions; this outline heuristic does not establish a WCAG failure.
Description
Heading levels describe a document’s structure.
Heading levels describe a document’s structure. A jump from one level to a much deeper level can prompt review of how readers navigate its sections.1
Finds adjacent upward jumps greater than one in supplied heading levels. Returns zero-based positions; this outline heuristic does not establish a WCAG failure.
When to use Heading Level h1–h6 Order Sequence Check
Use this for the following task: Finds adjacent upward jumps greater than one in supplied heading levels. Returns zero-based positions; this outline heuristic does not establish a WCAG failure.
Prepare the parsed attribute values, element states or ordered local lists requested below. Keep attribute presence separate from value.
How to use Heading Level h1–h6 Order Sequence Check and understand its results
- Prepare the parsed attribute values, element states or ordered local lists requested below. Keep attribute presence separate from value.
- Enter levels using the field table, then run the tool.
- Read skippedAt, hasUpwardSkips. Interpret flags, units, ordering and placeholder values using the rules below.
- Review any reported issue or failed check, correct the supplied values when appropriate, and verify the result in its intended context.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| levels | Levels | list of integer; minimum entries 0; maximum entries 10000; each entry: integer; minimum 1; maximum 6 | Required |
Supply levels in document order. Compare adjacent entries and return zero-based positions of jumps larger than one, together with an aggregate flag.2
skip at i when levels[i] > levels[i−1] + 1 This summarizes the declared operation. Units, indexing, inclusivity and exceptional cases are explained in the surrounding text.
| Output field | Meaning | Value type |
|---|---|---|
| skippedAt | Skipped At | list of integer |
| hasUpwardSkips | Has Upward Skips | boolean |
{
"input": {
"levels": [
1,
2,
4,
2,
3
]
},
"output": {
"skippedAt": [
2
],
"hasUpwardSkips": true
}
}Limitations and assumptions
Returning to a shallower level is not flagged. This is an outline heuristic, not a finding of a WCAG failure.
This evaluates supplied local information; it does not fetch a page or run a browser. Malformed requests produce input errors. A successfully evaluated request can still contain false flags, empty result lists or a result outside the supplied threshold; those outcomes have the meanings stated above.
Alternative or Complementary methods
Choose label for=id Binding Check for this operation: Resolves explicit label for binding from document-order IDs and labelability flags. An explicit for attribute uses the first matching ID; a nonlabelable first match prevents binding to a later duplicate. For a complementary task, use Valid ARIA Role Names Lookup for this operation: Classifies individual WAI-ARIA 1.2 role names in their recommended lowercase author spelling as concrete, abstract or unknown. This exact-spelling vocabulary lookup excludes extensions and browser case-insensitive processing.
Further background: HTML / accessibility reference: Heading Level h1–h6 Order Sequence Check.
References
Similar or alternative tools
- label for=id Binding Check
Resolves explicit label for binding from document-order IDs and labelability flags. An explicit for attribute uses the first matching ID; a nonlabelable first match prevents binding to a later duplicate.
- Valid ARIA Role Names Lookup
Classifies individual WAI-ARIA 1.2 role names in their recommended lowercase author spelling as concrete, abstract or unknown. This exact-spelling vocabulary lookup excludes extensions and browser case-insensitive processing.