> ## Documentation Index
> Fetch the complete documentation index at: https://docs.telophasehq.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Compression

> Control how Tangent compresses data before writing to sinks.

The `compression` block defines **how Tangent compresses serialized records** before they’re written to disk or uploaded to S3.\
Compression can be configured globally under `encoding`, or inline within a specific sink.

***

## Schema

<ParamField path="compression.type" type="string" required>
  Specifies which compression algorithm to use.

  **Options**

  * `none` — no compression
  * `gzip` — standard Gzip compression
  * `zstd` — modern Zstandard compression (fast, high ratio)
  * `snappy` — Snappy block compression (Avro-only)
  * `deflate` — Deflate stream compression (Avro-only)
</ParamField>

<ParamField path="compression.level" type="int">
  Compression level (optional).\
  Defaults vary by algorithm:

  | Algorithm | Default | Range  | Notes                           |
  | --------- | ------- | ------ | ------------------------------- |
  | `gzip`    | `6`     | `0–9`  | Higher = smaller output, slower |
  | `zstd`    | `3`     | `1–22` | Higher = smaller output, slower |
  | `snappy`  | —       | —      | Fixed speed/ratio               |
  | `deflate` | —       | —      | Typically used for Avro data    |
</ParamField>

***

## Behavior

* For **NDJSON** and **JSON**, Tangent compresses the entire file object.
* For **Avro** and **Parquet**, compression applies to **data blocks** inside the file. The file itself is not additionally wrapped.
* Tangent automatically appends appropriate file extensions:
  * `.gz` for Gzip
  * `.zst` for Zstd

***

## Examples

### Default (Zstandard level 3)

```yaml tangent.yaml icon=upload theme={null}
compression:
  type: zstd
  level: 3
```

### Gzip with level 9

```yaml tangent.yaml icon=upload theme={null}
compression:
  type: gzip
  level: 9
```

### No compression

```yaml tangent.yaml icon=upload theme={null}
compression:
  type: none
```

***

## Recommended Use

| Scenario                      | Recommended Compression     |
| ----------------------------- | --------------------------- |
| High-throughput pipelines     | `zstd` (fast and efficient) |
| Archival or long-term storage | `gzip`                      |
| Avro or Parquet encoding      | `zstd` or `snappy`          |
| Local testing                 | `none`                      |

***

## Defaults Summary

| Field               | Default | Description                        |
| ------------------- | ------- | ---------------------------------- |
| `compression.type`  | `zstd`  | Modern default for speed and ratio |
| `compression.level` | `3`     | Balanced performance               |

***

## See also

* [Encoding](/configuration/sinks/encoding)
* [S3 Sink](/configuration/sinks/s3)
* [File Sink](/configuration/sinks/file)