If you feel like selfhosting, OmniPoly is a great option.

Key Features:

• Translation: Text translation across multiple languages (see: libretranslate).

• Grammar Checking: Ensures your text is not only translated but also reads well with proper grammar and style (see: languagetool).

• AI-Powered Insights: Utilizes Large Language Models to analyze sentiments and extract interesting sentences, adding depth to your translations (see: ollama).

i just use google and deepl, maybe some yandex if i'm doing russian->english. would like a better alternative but i'm not aware of any.

Firefox and derivatives (e.g. Librewolf) have private built-in, on-device translation.

In my experience the kagi translator was the best

Apertus PublicAI is also capable to translate in a lot of lenguages, among other uses. Swiss made, privacy focused and FOSS. On eye level to the most advanced US AIs. It use the infrastructure of the Swiss National Supercomputing Centre (CSCS)

About Apertus

To be honest, Yandex's proprietary services are irreplacable and significantly better than Google. Many more languages too.

https://codeberg.org/ManeraKai/simplytranslate

https://codeberg.org/aryak/mozhi

https://github.com/LibreTranslate/LibreTranslate

https://codeberg.org/gospodin/translite

Linguist extension (Chromium/ Firefox)

• Modular translators system
• You can use any translation service like Google, Yandex, Bing, DeepL, ChatGPT, etc.
• Custom translators: you can use your own translator module
• Offline translation. With embedded Bergamot translator, you can translate texts right on your device. Keep your privacy
• All-in-one translation solution
• Full-page translation with flexible auto-translation configuration
• Highlighted text translation
• Translate any text input
• Dictionary with saved translations
• Translations history, to remember recently translated words
• Text-to-speech (TTS)

or Crow Translate on Desktop

• Translate and speak text from screen or selection
• Support 125 different languages
• Low memory consumption (~20MB)
• Highly customizable shortcuts
• Command-line interface with rich options
• D-Bus API
• Available for Linux and Windows

mozhi

There should be more on https://alternativeto.net/ when you search "DeepL" for alternatives

Since many are listed here but I am sure there are more

I use the FluentRead browser extension with a locally-hosted LLM.

For phone? Android? Do you need to translate photos (restaurant menus, signs on the street, etc...)?

Stay with DeepL

I'd stay away from Yandex. Former user here is excellent but: https://arstechnica.com/security/2025/06/meta-and-yandex-are-de-anonymizing-android-users-web-browsing-identifiers/