Translation API Comparison: DeepL vs MyMemory vs GPT-5-nano vs Gemini
WhisperSubTranslate supports four translation services. Each has its strengths and limitations. This guide helps you choose the right one for your needs.
Quick Comparison
| Feature | MyMemory | DeepL | GPT-5-nano | Gemini |
|---|---|---|---|---|
| Free Tier | 50,000 chars/day | 500,000 chars/month | Pay per use ($0.05/1M input) | ~250 subs/day free |
| API Key Required | No | Yes | Yes | Yes (Free) |
| Quality | Good | Excellent | Excellent | Excellent |
| Speed | Fast | Fast | Very Fast | Very Fast |
| Context Awareness | Low | High | Very High | Very High |
Detailed Analysis
MyMemory FREE
A free translation API that's great for getting started. No registration or API key required.
Pros
- Completely free
- No API key needed
- Easy to start
- 50,000 chars/day
Cons
- Lower quality
- Limited context
- Daily limits
- Fewer languages
DeepL RECOMMENDED
Professional-grade translation with excellent quality. Free tier available with generous limits.
Pros
- Excellent quality
- Natural phrasing
- 500K chars/month free
- Fast processing
Cons
- API key required
- Registration needed
- Limited languages
- Paid for heavy use
GPT-5-nano FAST & CHEAP
OpenAI's fastest and most affordable GPT-5 model. Optimized for high-throughput tasks like subtitle translation with excellent quality.
Pros
- Very fast processing
- Lowest cost ($0.05/1M input)
- Great context awareness
- 100+ languages supported
Cons
- Pay per use only
- API key required
- Less reasoning depth
- OpenAI account needed
Gemini 3 Flash FREE API
Google's fast and capable AI model. Free API key with generous daily limits, making it an excellent choice for most users.
Pros
- Free API key available
- ~250 subtitles/day free
- Very fast processing
- Excellent context awareness
Cons
- API key required
- Daily request limits
- Google account needed
- Paid for heavy use
Recommendations by Use Case
Casual/Personal Use
Recommended: MyMemory - Free and easy to start. Good enough for personal videos and informal content.
YouTube Creators
Recommended: DeepL - Professional quality at a reasonable cost. The free tier is usually sufficient for most creators.
Professional/Commercial
Recommended: DeepL or GPT-5-nano - Both offer excellent quality. DeepL for European languages, GPT-5-nano for speed and Asian languages.
Movies/TV Shows
Recommended: GPT-5-nano - Fast processing with good context awareness. Very cost-effective for large subtitle files.
Pro Tip: Start with MyMemory to test your workflow, then upgrade to DeepL for production content. The quality difference is noticeable but MyMemory is great for drafts.
Setting Up Each Service
MyMemory
No setup required! Just select MyMemory in WhisperSubTranslate settings and start translating.
DeepL
- Visit deepl.com/pro-api
- Create a free account
- Copy your API key from the account page
- Paste it in WhisperSubTranslate settings
GPT-5-nano (OpenAI)
- Visit platform.openai.com/api-keys
- Create an account and add payment method
- Generate an API key (starts with
sk-proj-orsk-) - Paste it in WhisperSubTranslate settings
Gemini (Google AI)
- Visit Google AI Studio
- Sign in with your Google account
- Click "Create API key" to generate a free key
- Paste it in WhisperSubTranslate settings
Why GPT-5-nano? It's the fastest and cheapest model in OpenAI's GPT-5 family. Perfect for subtitle translation: $0.05 per 1M input tokens, $0.40 per 1M output tokens. A typical 2-hour movie subtitle costs about $0.05 (less than 100 won) to translate!
Why Gemini? Free API key with ~250 subtitle lines per day (~20-30 min of video). Google's Gemini 3 Flash model offers excellent quality and speed. Great for casual users who want AI-quality translation without paying!