Translation API comparisons often produce the wrong answer because they mix a headline rate with another provider's bill after included usage. They also copy retired plans for years after a provider changes pricing.
This guide uses a consistent method. Prices change, so verify every provider's live pricing page before procurement.
The fair-comparison formula
For each provider, record:
- billing period and currency;
- subscription or base fee;
- included characters or credits;
- overage rate after included usage;
- whether input, output, markup or minimum request sizes are billed;
- document, custom-model and glossary charges;
- volume limits and discounts;
- the date and source URL used.
Then calculate the total for exactly the same workload. Do not call an included allowance “no free tier”, and do not compare one provider's $/M rate with another provider's total at one million characters.
Current plan structures
| Provider | Current structure | Source to verify |
|---|---|---|
| Google Cloud Translation Basic | First 500K chars/month covered by a $10 credit, then $20/M for standard NMT up to 1B | Google pricing |
| DeepL | Developer: 1M total; Growth: recurring included usage + subscription + overage | DeepL plan selection |
| Azure Translator | Free and paid Azure tiers; verify region, tier and current allowance | Azure pricing |
| Amazon Translate | Pay as you go; verify current introductory allowance and feature-specific rates | AWS pricing |
| Langbly | First 500K input chars/month included, then $5/M additional input chars; no base fee | Langbly pricing |
Google and Langbly: an equal-basis example
Google Cloud Translation Basic and Langbly both include the first 500,000 characters each month. This produces the following totals for standard text usage:
| Monthly input | Google Basic | Langbly | Difference |
|---|---|---|---|
| 500K | $0 | $0 | Both included |
| 1M | $10 | $2.50 | 75% |
| 5M | $90 | $22.50 | 75% |
| 25M | $490 | $122.50 | 75% |
| 100M | $1,990 | $497.50 | 75% |
These totals assume the published standard text rates and one target-language workload. They exclude document translation, custom models, taxes and negotiated enterprise terms.
Why DeepL needs a different calculation
DeepL API Free and API Pro can no longer be purchased. Developer includes one million characters in total for evaluation. Growth includes recurring usage and overage, with the included amount depending on monthly or annual billing.
Insert the live Growth subscription and overage into your workload. A static comparison based on the retired API Pro rate is not current.
Langbly billing details
- Payment details are required to activate API access.
- The first 500,000 input characters each month are included.
- Additional usage costs $5 per million input characters.
- There is no monthly API base fee.
- Eligible translated responses may be cached for up to one hour.
- Idempotent responses may be retained for up to 24 hours.
Questions to ask before choosing
- Which language pairs and content types are representative?
- Is the API format already embedded in production?
- Do you need documents, glossaries, formality or custom instructions?
- What retention and regional-processing requirements apply?
- How much engineering and review time does migration require?
- What is the total bill after included usage at normal and peak volume?
Run a quality evaluation and a cost calculation side by side. The cheapest rate is not valuable if the workflow creates more human review or migration work.