“Free translation API” can mean a permanent allowance, a one-time evaluation grant, an introductory cloud credit or a self-hosted project. Treating these as the same thing leads to poor purchasing decisions.
This comparison was verified in July 2026. Always check the provider's live terms before integrating.
Current options at a glance
| Provider | Included/evaluation usage | Payment setup | What happens next |
|---|---|---|---|
| Langbly | First 500K input chars each month | Payment details required | $5/M additional input chars |
| Google Cloud Translation | First 500K chars each month via $10 credit | Google Cloud billing account | $20/M standard NMT up to 1B |
| DeepL Developer | 1M chars total | Check current signup | Growth for recurring production usage |
| MyMemory | Public rate-limited access | Depends on usage | Contact provider for higher limits |
| LibreTranslate | Self-hosted software | Your own infrastructure | You operate and fund hosting |
Langbly
Langbly follows the Google Translate v2 request and response format. Payment details are required to activate API access. The first 500,000 input characters each month are included, then additional usage costs $5 per million input characters with no base fee.
Use the allowance to test representative language pairs, HTML, placeholders, terminology and error handling. Do not assume a general quality claim applies to your content.
Google Cloud Translation
Google Cloud Translation covers the first 500,000 characters each month through a $10 monthly credit. Standard NMT usage after that is $20 per million characters up to one billion characters. New Google Cloud customers may separately qualify for an introductory cloud credit.
A Google Cloud project and billing account are required. Include setup, authentication and any Advanced or document features in your evaluation.
DeepL Developer
DeepL API Free and API Pro can no longer be purchased. Developer now provides one million characters in total for development and evaluation. It is not a recurring monthly allowance.
For production, DeepL Growth combines a subscription, included usage and overage. Check the live Growth plan rather than using the retired API Pro rate.
MyMemory and LibreTranslate
MyMemory can be useful for small experiments but has rate limits and different commercial routes for larger use. Verify its current limits and privacy terms before production.
LibreTranslate is open source and can be self-hosted. “Free” then refers to software licensing, not zero operating cost: hosting, monitoring, scaling and model quality remain your responsibility.
How to evaluate responsibly
- Create a representative set of real content and difficult language pairs.
- Test placeholders, HTML, terminology, tone and long inputs.
- Have fluent speakers review a blinded sample.
- Measure latency, errors and retry behavior.
- Compare the total monthly bill after included usage.
- Review retention, subprocessors and regional processing.
Frequently asked questions
Does Langbly require payment details?
Yes. Payment details are required to activate API access. The first 500,000 input characters each month are included.
Does Google Cloud Translation have monthly included usage?
Yes. Google covers the first 500,000 characters each month through a $10 monthly credit, then charges its published standard NMT rate.
Is DeepL API Free still available?
No. DeepL says API Free and API Pro can no longer be purchased. Developer is the current evaluation plan.