# Add\_field parameter in filter plugins
**URL:** https://discuss.elastic.co/t/add-field-parameter-in-filter-plugins/37333
**Category:** Logstash
**Created:** [December 16, 2015, 9:50am UTC](https://discuss.elastic.co/t/add-field-parameter-in-filter-plugins/37333 "2015-12-16T09:50:31Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@srinivas](https://discuss.elastic.co/u/srinivas)
#### Post date: [December 16, 2015, 9:50am UTC](https://discuss.elastic.co/t/add-field-parameter-in-filter-plugins/37333/1 "2015-12-16T09:50:32Z")
Hi,
Can anyone explain what does add\_field do ?
`filter { mutate { add_field => { "COLUMN2" => "%{COLUMN1}" } } }`
What is the difference between add\_field present in mutate, clone, kv and grok plugins
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [December 16, 2015, 10:24am UTC](https://discuss.elastic.co/t/add-field-parameter-in-filter-plugins/37333/2 "2015-12-16T10:24:08Z")
> Can anyone explain what does add\_field do ?
It adds a field to the current event. I don't know how to explain that in any different way.
> What is the difference between add\_field present in mutate, clone, kv and grok plugins
With the exception of mutate, add\_field and remove\_field only apply if the filter was successful (where the meaning of success depends on the filter). In other words,
```auto
filter {
grok {
match => ["foo", "..."]
remove_field => ["foo"]
}
}
```
is a convenient way of parsing a field with grok and deleting the original field only if the grok match was successful.
---
### Author:  [@srinivas](https://discuss.elastic.co/u/srinivas)
#### Post date: [December 16, 2015, 10:53am UTC](https://discuss.elastic.co/t/add-field-parameter-in-filter-plugins/37333/4 "2015-12-16T10:53:55Z")
> [@srinivas](#):
>
> adds a field means is that added as a new column in es index if output is an elasticsearch index
adds a field means is that added as a new column in es index if output is an elasticsearch index
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [December 16, 2015, 11:37am UTC](https://discuss.elastic.co/t/add-field-parameter-in-filter-plugins/37333/5 "2015-12-16T11:37:08Z")
> adds a field means is that added as a new column in es index if output is an elasticsearch index
Elasticsearch has no "column" concept, but yes.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 5:18am UTC](https://discuss.elastic.co/t/add-field-parameter-in-filter-plugins/37333/6 "2017-07-06T05:18:12Z")