How to Translate ASS/SSA Subtitle Files

Copying into Google Translate or ChatGPT

The most common approach — and the one that fails most often. When you paste raw ASS dialogue into a general-purpose translator, several things go wrong:

1. Override tags get translated. A tag like \fnArial (set font to Arial) might get "translated" into nonsense because the engine treats it as text.
2. Curly brackets get removed or doubled. Many translators strip special characters or reformat them.
3. Line breaks change. ASS uses \N for hard line breaks and \n for soft wraps. Translators often convert these to actual newlines, destroying the intended layout.
4. Line count changes. If the translator merges or splits lines, the one-to-one mapping between original and translated dialogue is lost, and timestamps no longer match.
5. Character encoding breaks. ASS files use specific encodings per style. A translator that outputs in a different encoding can produce garbled characters when the file is loaded in a player.

Converting to SRT First, Then Translating

Some people convert ASS to SRT, translate the simpler format, then convert back. This is cleaner, but you lose everything that makes ASS worth using:

• -All style definitions are stripped
• -Positioning and motion effects disappear
• -Karaoke timing is discarded
• -Layer ordering (for overlapping text) is flattened
• -Vector drawings are removed entirely

If your ASS file is plain dialogue with no special effects, this might be acceptable. But if someone invested time in typesetting — and they usually have — you're throwing away that work.

Using Subtitle Edit or Aegisub Manually

Aegisub is the gold-standard editor for ASS files. You can absolutely translate line by line in Aegisub, preserving all formatting. The downside is obvious: it's manual work. For a 24-episode anime series with 300+ lines per episode, you're looking at days of tedious copy-paste-translate cycles. And if you're not fluent in the target language, you still need a machine translation engine — bringing you back to the tag-preservation problem.

Title Card — Multi-Layer Glow Effect

The opening title uses two layers — Layer 0 with \blur6 creates a dark glow behind the text, and Layer 1 renders the sharp title on top. After translation, "SINTEL" becomes "シンテル" and "A Blender Foundation Open Movie" becomes "Blender Foundation制作のオープンムービー". Both layers, the blur effect, the fade animation (\fad), and the centered positioning (\an5\pos(960,460)) are all preserved exactly.

Scene 1 — Positioned Signs, Scene Label, and Colored Dialogue

This is the most demanding test — three different ASS features visible simultaneously:

• TopNote (top-left): "Scene 1 — The Shaman's Hut" → "シーン1 — シャーマンの小屋" — uses BorderStyle=3 for an opaque background box, positioned at \an7\pos(60,35)
• Sign (right side): "⚔ The Gatekeepers' Land ⚔" → "× 門番たちの土地 ×" — positioned with \pos(1560,180) and rotated with \frz-8
• Dialogue (bottom): "This blade has a dark past." → "この刃には暗い過去がある。" — uses the italic serif Shaman style with the word "dark" highlighted in a different color via \c&H4466FF&\b1

All three elements maintain their exact screen positions, rotation angles, colors, and formatting after translation.

Karaoke — Syllable-by-Syllable Timing

The end credits song uses \k tags for karaoke syllable timing. "I wandered through the frozen lands alone" becomes "凍てつく地をひとりさまよい". The orange highlight that sweeps through each syllable is driven by \k duration values (e.g., \k58, \k42, \k38), and these timing values stay completely untouched — only the text between them changes.

End Title — Fade, Blur, and Scrolling Credits

The closing sequence combines multiple effects: a multi-layer glowing title ("SINTEL" → "シンテル"), a fade-out subtitle ("The End" → "おしまい"), and a scrolling credits line using \move(1920,980,0,980) that slides across the bottom of the screen. The scrolling text was translated from English to Japanese while maintaining the exact same motion path.

Go to doc2lang.com (or directly to doc2lang.com/ass-translate). You'll see the upload area in the center of the page — just drag and drop your .ass file, or click "Upload a file" to browse. Doc2Lang handles Subtitles alongside PDF, Excel, Word, and other file types. You can also upload multiple files at once or a ZIP archive containing an entire season.

After uploading, a settings dialog appears. Choose your source language (English) and target language (Japanese) from 100+ options. Then pick a translation style — for Sintel's movie dialogue, we selected "Casual — Natural and conversational tone", which produces the most natural-sounding results for entertainment content. You can also add a Glossary to keep character names consistent (e.g., adding "Scales" → "スケールズ" to prevent the AI from translating the dragon's name differently each time). When everything's set, click Upload to start the translation.

Doc2Lang generates a free preview before you pay. The Translation Preview page shows your file name, the detected language pair, and the document type.

Click "Content Preview" to expand the translation table. You'll see the original text on the left and the translated text on the right — side by side. This is where you check whether the translation quality meets your expectations. Only the dialogue text is shown here; all the ASS formatting tags (\pos, \k, \fad, etc.) are preserved in the actual file but hidden from this preview for readability.

If you're not satisfied with the translation quality, click "Adjust Settings" to change the translation style or language and try again — at no cost. You can also click "Download Sample File" to get a partial translation as a free .ass file and test it in your video player before committing.

Once you're happy with the preview, click "Translate the Entire File". A purchase dialog appears showing the credit cost for your file. You have two payment options: use pre-purchased credits ("Pay with Credits") or pay directly for this specific file ("Pay Directly"). No subscription is required — it's completely pay-as-you-go.

After payment, the fully translated .ass file is ready for download. Open it in VLC alongside your video (via Subtitle → Add Subtitle File) to verify that all the positioning, colors, karaoke timing, and layer effects survived the translation.