Config: Format Section

Some of the Fluentd plugins support the <format> section to specify how to format the record.

Format Section Overview

The format section can be under <match> or <filter> section.

<match tag.*>
  @type file
  # ...
    # ...

Formatter Plugin Type

The @type parameter of <format> section specifies the type of the formatter plugin. Fluentd core bundles some useful formatter plugins.

  @type json

Here's the list of built-in formatter plugins:

Third-party plugins may also be installed and configured.

For more details, see plugins documentation.



The @type parameter specifies the type of the formatter plugin.

  @type csv
  # ...

Time Parameters

  • time_type (enum) (optional): parses/formats value according to this


    • Default: float

    • Available values: float, unixtime, string

      • float: seconds from Epoch + nano seconds (e.g.


      • unixtime: seconds from Epoch (e.g. 1510544815)

      • string: use format specified by time_format, local time or time


  • time_format (string) (optional): processes value according to the

    specified format. This is available only when time_type is string.

    • Default: nil

    • Available time format:

      • For more details about formatting, see


      • For more details about parsing, see


      • %iso8601 (only for parsing)

      • Use %N to parse/format with sub-second precision, because

        strptime does not support

        %3N, %6N, %9N, and %L.

  • localtime (bool) (optional): if true, uses local time. Otherwise,

    UTC is used. This is exclusive with utc.

    • Default: true

  • utc (bool) (optional): if true, uses UTC. Otherwise, local time is

    used. This is exclusive with localtime.

    • Default: false

  • timezone (string) (optional): uses the specified timezone. One can

    parse/format the time value in the specified timezone format.

    • Default: nil

    • Available time zone format:

      1. [+-]HH:MM (e.g. "+09:00") (recommended)

      2. [+-]HHMM (e.g. "+0900")

      3. [+-]HH (e.g. "+09")

      4. Region/Zone (e.g. Asia/Tokyo)

      5. Region/Zone/Zone (e.g. America/Argentina/Buenos_Aires)

If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is an open-source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.

Last updated