How to Translate Substack From English to Japanese (Step-by-Step)

Reading English content on a Substack is easy, but sometimes you want the meaning in your own language. Japanese is spoken by millions, and being able to read an English post in Japanese — while keeping the English original in view — is ideal for learning and for getting the nuance exactly right.

This guide shows how to translate an English Newsletter into Japanese in place, with the English source staying visible so you can compare the two.

Demo note: the screenshots below are built in a real Substack layout to show exactly how BothLang displays a bilingual page — the English paragraph on top and the Japanese translation directly beneath, with a hand-drawn arrow pointing at the translation.

What you need

• BothLang installed in Chrome, Edge, or Firefox — see the download page.
• The extension pinned to your toolbar.
• An English Newsletter open in a tab.

Step 1 — Open the English Newsletter

Open the English piece you want to read.

Step 2 — Set Japanese as your target language

Click the BothLang icon. Set Translate into to Japanese and Page display to Bilingual.

Step 3 — Translate the page

Click Translate Now. BothLang places a Japanese translation directly beneath each English paragraph, leaving the English intact. A hand-drawn arrow marks the first translated paragraph.

Step 4 — Switch reading modes

• Bilingual — English and Japanese together.
• Translation only — fastest.
• Original only — back to clean English.

The short version

1. Install and pin BothLang.
2. Open an English Newsletter.
3. Set Translate into: Japanese, Page display: Bilingual.
4. Click Translate Now.
5. Read the Japanese with the English original underneath.

Try it on your next English Newsletter.