About LUMIERE
Professional Subtitle Translation
LUMIERE is a web-based tool that translates subtitle files into fluent English using state-of-the-art AI models. Upload your file, translate, review with professional QC tools, and export — all in the browser.
How It Works
01
Upload
Drag and drop your SRT or VTT subtitle file. LUMIERE instantly parses the file, preserving all timecodes and formatting.
02
Detect Language
The source language is automatically detected from your subtitle content with a confidence indicator. You can also set it manually.
03
Translate
Pro subscribers get one-click AI translation powered by Claude (Anthropic) or GPT-4o (OpenAI). Subtitles are translated in batches with a live progress indicator.
04
Review & Edit
Use the side-by-side editor to review translations. Character count, reading speed (CPS), and line length warnings help you spot issues instantly.
05
Export
Download your translated file in the exact same format with all original timecodes preserved. Or copy to clipboard for pasting elsewhere.
Supported Formats
.SRT
SubRip — the most common subtitle format used in film and video production
.VTT
WebVTT — the standard format for web video, used by HTML5 video players
.SUB
MicroDVD — frame-based subtitle format supported for import
Supported Languages
LUMIERE can translate from any of these languages into English:
Korean
Japanese
Chinese (Simplified)
Chinese (Traditional)
Spanish
French
German
Italian
Portuguese
Russian
Arabic
Hindi
Thai
Vietnamese
Indonesian
Turkish
Dutch
Polish
Swedish
Danish
Norwegian
Finnish
Czech
Romanian
Hungarian
Frequently Asked Questions
Do you store my subtitle files?
No. Your subtitle content is processed in real-time and never saved to our servers. Once the translation is returned to your browser, the data is discarded. See our
Privacy Policy for full details.
Which AI models do you use?
LUMIERE offers two AI translation engines: Claude Sonnet 4.5 by Anthropic (default) and GPT-4o Mini by OpenAI. Both produce high-quality, natural-sounding translations. You can switch between them before translating.
Can I use my own API keys?
Yes. LUMIERE supports "Bring Your Own Key" (BYOK) mode. Free users can paste their own Anthropic or OpenAI API key to use AI translation without a Pro subscription. Your keys are stored only in your browser and never sent to our servers.
How do I cancel my subscription?
Go to your
Account page and click "Manage Subscription." This opens the Stripe Customer Portal where you can cancel, update your payment method, or view invoices. Your Pro access remains active until the end of the current billing period.
Do I own my translations?
Yes, completely. You retain full ownership of all subtitle files and translations produced through LUMIERE. We claim no rights to your content.
Are translations perfect?
AI translations are remarkably good but not infallible. LUMIERE provides professional QC tools — character count, reading speed, line length warnings — to help you spot and fix issues. We always recommend a human review pass for production use.
What happens to my timecodes?
Timecodes are never modified. LUMIERE only translates the text content — all timing, numbering, and formatting are preserved exactly as in your original file. The QC dashboard verifies this automatically.