---
title: "The Bing Spell Check API lets you perform contextual grammar and spell checking. Bing has developed a web-based spell-checker that leverages machine learning and statistical machine translation to dynamically train a constantly evolving and highly contextual algorithm. The spell-checker is based on a massive corpus of web searches and documents."
method: POST
path: "/spellcheck"
tags: ["SpellCheck"]
---

# The Bing Spell Check API lets you perform contextual grammar and spell checking. Bing has developed a web-based spell-checker that leverages machine learning and statistical machine translation to dynamically train a constantly evolving and highly contextual algorithm. The spell-checker is based on a massive corpus of web searches and documents.

`POST /spellcheck`

## Query parameters

- `ActionType` 'Edit' | 'Load'
- `AppName` string
- `cc` string
- `ClientMachineName` string
- `DocId` string
- `mkt` string
- `SessionId` string
- `SetLang` string
- `UserId` string
- `Mode` 'proof' | 'spell'
- `PreContextText` string
- `PostContextText` string
- `Text` string, required

## Headers

- `X-BingApis-SDK` 'true', required
- `Accept` string
- `Accept-Language` string
- `Pragma` string
- `User-Agent` string
- `X-MSEdge-ClientID` string
- `X-MSEdge-ClientIP` string
- `X-Search-Location` string

## Response `200`

Success.

- SpellCheck
  - `_type` string, required

## Other responses

- `default` — An error has occurred. Check the response type and/or status code for more details.

## Changes

- **2026-07-13** `56e997ef1fe6` — 1 breaking, 3 info
  - added the new required `query` request parameter `Text`
  - added the new optional `query` request parameter `Mode`
  - added the new optional `query` request parameter `PostContextText`
  - added the new optional `query` request parameter `PreContextText`
- **2018-07-06** `1c4948975697` — 4 warning
  - deleted the `query` request parameter `Mode`
  - deleted the `query` request parameter `PostContextText`
  - deleted the `query` request parameter `PreContextText`
  - deleted the `query` request parameter `Text`

[Change history](https://skmtc.dev/azure/apis/spell-check-client/changes/spellcheck/post.md)

---

[API](https://skmtc.dev/azure/apis/spell-check-client.md) · [All operations](https://skmtc.dev/azure/apis/spell-check-client/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/azure/spell-check-client/revisions/56e997ef1fe6/schema)