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

# Compare With Previous

> Detect a meaningful change and update state after success. Exact configuration, ports, placement, and execution behavior.

**Node type:** `compare_previous` · **Version:** `1` · **Category:** Logic

Detect a meaningful change and update state after success. This node can change external state or produce an external side effect.

## Configuration

| Field           | Type   | Default  | What it controls                                                                                                 |
| --------------- | ------ | -------- | ---------------------------------------------------------------------------------------------------------------- |
| `key`           | string | `""`     | Workflow-scoped state key.                                                                                       |
| `value`         | any    | `null`   | Literal value, protected reference, or mapped output.                                                            |
| `normalization` | string | `"trim"` | Text normalization applied before change comparison. Values: `trim`, `lowercase`, `collapse_whitespace`, `none`. |

<Note>The new comparison value is committed only after the complete workflow succeeds.</Note>

## Workflow JSON

The editor stores this node with the following implemented default configuration:

```json title="Default node configuration" theme={"system"}
{
  "type": "compare_previous",
  "version": 1,
  "configuration": {
    "key": "",
    "value": null,
    "normalization": "trim"
  }
}
```

Values may be entered literally or mapped from an earlier compatible output when the inspector exposes a mapping control. See [Variables and data mapping](/workflows/variables-and-data).

## Inputs

| Port    | Type     | Required | Description   |
| ------- | -------- | -------- | ------------- |
| `key`   | `string` | Yes      | Key           |
| `value` | `any`    | Yes      | Current value |

## Outputs

| Port       | Type      | Required | Description |
| ---------- | --------- | -------- | ----------- |
| `changed`  | `boolean` | No       | Changed     |
| `previous` | `any`     | No       | Previous    |
| `current`  | `any`     | No       | Current     |

## Where it can run

* Desktop local runner
* Paired self-hosted runner
* Hosted runner

## Test and inspect

Use **Test node** in the editor to preview this step with the current configuration. A full run records resolved inputs, outputs, logs, duration, and any artifacts in the execution inspector. Side-effecting or destructive nodes can require an additional confirmation or approved workflow permission.