You can use the translator on the homepage without creating an account. Choose the source language and a supported target, then enter your text. Results stream into the translation pane as they are generated.
The homepage accepts up to 4,000 characters. Automatic translation waits for a completed word or a pause in typing, so you can write naturally. Longer passages use more of the shared minute allowance; leave time between large requests.
To connect an application, create an account, verify your email, and create a named API key. Save its secret when it appears: it is shown only once. The documentation at /docs includes a copyable request and the expected JSON response.
API requests use POST /v1/translate with text, source_language and target_language. The API input limit is 768 UTF-8 bytes, which is different from the homepage character limit. Accounts start with 10,000 requests per UTC day, shared across their keys.
Before relying on a result, check names, numbers, tone and meaning. Some language directions are experimental, and Portuguese has known wrong-language failures. The language page explains which directions are available and their quality status.