Description
Format an explicit MIME media type and ordered parameter observations with token/quoted value serialization; preserves duplicates, no registered-value canonicalization.
A media type has a type/subtype token and may carry named parameters. Multipart content uses explicit boundary delimiter lines around its parts. Token case rules, parameter quoting, repeated records and exact line endings affect how a representation is interpreted; a lexical check is narrower than parsing a complete message.1
Format an explicit MIME media type and ordered parameter observations with token/quoted value serialization; preserves duplicates, no registered-value canonicalization.
When to use this tool
Use this tool to format an explicit MIME media type and ordered parameter observations with token/quoted value serialization; preserves duplicates, no registered-value canonicalization.
How to use the tool and how it works
- Enter mediaType, parametersJson using the field definitions below. For JSON text, serialize the explicit records in the shown shape.
- Run the operation. Correct input errors before interpreting an output.
- Read result.value. Use the ordering, boundary rules and absence conditions described below.
Normalize media type and parameter names, preserve parameter values and order, and format the combined field value with conditional quoting.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| mediaType | Bare type/subtype text without a parameter suffix. | Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies. |
| parametersJson | JSON text encoding array of {name: string, value: string}. Keep the record keys and value types shown in the decoded example below. | Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies. |
These are the decoded structures used in the example’s JSON text fields. Supply the corresponding serialized JSON strings as input.
{
"parametersJson": [
{
"name": "charset",
"value": "utf-8"
}
]
}| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.value | Formatted normalized media-type field value. |
{
"input": {
"mediaType": "Text/HTML",
"parametersJson": "[{\"name\":\"charset\",\"value\":\"utf-8\"}]"
},
"output": {
"result": {
"value": "text/html; charset=utf-8"
}
}
}Limitations and assumptions
- Duplicate parameters are preserved, not resolved, and a complete MIME message is not generated.
- Supported boundary strings contain 1–70 characters from the declared MIME boundary subset and cannot end in a space. Single-byte envelope budgets are distinct from UTF-8 text byte counts and from a complete MIME transport.
- Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
- Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.
Alternative or Complementary methods
Choose the target media-type and multipart conventions explicitly. Use a complete MIME parser for nested messages and encodings; these record and delimiter tools handle only their stated representations.
References
-
RFC 2046: MIME Media Types — RFC Editor
-
Tool behavior and example: Media Type Record Formatter — tool.io
Similar or alternative tools
- Media Type Offer Specificity Order
Stable-order bare MIME ranges by exact/type-wildcard/all-wildcard specificity only; excludes qualities, parameters and offer preference.
- Media Type Parameter Conflict Table
Audit conflicting decoded MIME parameter values under case-insensitive names and case-sensitive literal values; no registered-parameter equivalence inference.