No subscription, no paid tier. The only bill that can exist is the one from the model provider you choose, and this page shows roughly what that is.
The extension and the apps are free: no purchase, no subscription, no paid tier, no in-app purchase and no advertising, on Safari for iPhone, iPad and Mac, and on Chrome and Firefox. The source code is public under GPL-3.0, so the free part is not a trial. The only cost that can exist is the translation itself. A free channel needs no key and no account, and covers everyday reading with general-purpose machine translation. If you want an AI model, you add your own API key and the model provider bills you directly at their published prices; the extension neither marks that up nor takes a cut, and never sees the bill. After signing in you can also claim a small free credit paid for by us, described below.
Less than most people expect, because translation is short output for short input. On the budget model used behind our free credit, a typical article-length page costs roughly 0.0004 US dollars — about 2,500 pages per dollar. Mid-range models from the major providers usually land between a tenth of a cent and a cent per page; a long Wikipedia article on DeepSeek costs well under a cent. Read-aloud and transcription are the expensive features, because they are billed per minute of audio rather than per page, so a few minutes of speech can cost more than a whole afternoon of reading. The setup guide lists measured latency and per-request cost for each engine we recommend, taken from our own probes rather than from marketing pages, so you can pick by price before you paste a key.
After you sign in, you can claim a credit of about 0.20 US dollars that we pay for. It works for translation, read-aloud and transcription and is enough for a few hundred pages of reading, which is the point: to let you see whether an AI engine is worth setting up before you create any account with a provider. The catch is stated plainly. On that path your text passes through our relay on its way to the model provider, because the relay is what meters the credit; we do not store the text and we do not log it. The credit is pinned to one inexpensive model, and when it runs out the extension stops and shows two ways forward — add your own key, or join the community — rather than silently switching you to anything paid. There is no way to buy more credit from us, by design.
The China edition (大肚猴翻译, a separate app on the mainland App Store) is also free, with the same rule that translation is billed by the provider you choose. It does not include the free credit we pay for, because that credit is metered through a server outside mainland China. Instead, the settings screen points you to the free allowance that Alibaba Cloud's Model Studio gives new accounts on its own models, and configures translation, read-aloud and transcription from that one key. That allowance is Alibaba Cloud's, not ours, and its size and validity are whatever their page says at the time.
No subscription is planned and the project's design rules say so in writing: the free path must not depend on a server of ours, and nothing that is free today may be moved behind a paywall later. Costs we choose to carry — the small free credit, the sync storage quota — are capped by design rather than recovered from users. If you want to support the project, the useful things are bug reports with the page that broke, a rating on the store you installed from, and telling someone who reads in two languages.