---
title: "Preview Column Conversion"
method: GET
path: "/api/tf/tables/{table_id}/columns/{column_id}/convert-preview"
tags: ["tableflow"]
---

# Preview Column Conversion

`GET /api/tf/tables/{table_id}/columns/{column_id}/convert-preview`

## Request

- Base URL: `https://api.tintin-x.com` (the document declares no server; this is the origin it was published from)
- URL: `https://api.tintin-x.com/api/tf/tables/{table_id}/columns/{column_id}/convert-preview`
- Auth: HTTP bearer

Preview a type conversion before commit.

Returns whether the transition is allowed and how many existing
cell values would drop to null. The FE shows this in the confirm
modal so the user knows what they're losing.

## Path parameters

- `table_id` string, uuid, required
- `column_id` string, uuid, required

## Query parameters

- `target` string, required

## Response `200`

Successful Response

- ColumnConversionPreview: Response for GET /columns/{id}/convert-preview?target=<type>. `will_drop_count` = cells whose value can't coerce to the target type; they'll become tombstones if the user proceeds.
  - `allowed` boolean, required
  - `impacted_count` integer, required
  - `will_drop_count` integer, required

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/tintin-x/apis/tintin-api.md) · [All operations](https://skmtc.dev/tintin-x/apis/tintin-api/llms.txt) · [OpenAPI document](https://skmtc.dev/tintin-x/apis/tintin-api/revisions/8839a8d0a66c?raw)