Pricing comparison
Real pricing based on monthly character volume. All prices in USD.
| Volume | Langbly | GPT-4o | DeepL | Google NMT | You Save |
|---|---|---|---|---|---|
| 1M chars | $19 | $7.50 | $25 | $20 | Save up to 24% |
| 5M chars | $19 | $37.50 | $125 | $100 | Save 49–85% |
| 25M chars | $69 | $187.50 | $625 | $500 | Save 63–89% |
| 100M chars | $199 | $750 | $2,500 | $2,000 | Save 73–92% |
Feature comparison
| Feature | Langbly | GPT-4o | DeepL | Google NMT |
|---|---|---|---|---|
| Translation approach | Optimized AI | General-purpose AI | Neural MT | Neural MT |
| Context understanding | Limited | |||
| Formality control | Via prompt | |||
| Consistent output | Variable | |||
| Speed (latency) | ~500ms | 1-3s | ~200ms | ~100ms |
| Hallucination risk | Mitigated | Moderate | Very low | Very low |
| API simplicity | Google v2 | Chat API | REST | REST |
| Batch support | Manual | |||
| HTML preservation | Unreliable | |||
| Locale rules | Built-in | Via prompt | Basic | |
| Free tier | 500K/mo | 500K/mo | $300 credit |
Advanced AI vs NMT: What's the difference?
Neural Machine Translation (NMT), used by DeepL and Google, is purpose-built for translation. It's fast, consistent, and affordable. But it translates sentence-by-sentence without understanding broader context.
Advanced AI models, like GPT-4, understand context, tone, and intent. They can handle idioms, cultural references, and ambiguous text that NMT systems struggle with. The trade-off: higher cost, slower speed, and occasional hallucinations.
Why Langbly is the best of both worlds
Langbly uses advanced AI translation with production guardrails that solve the main problems of using GPT-4 directly:
- Optimized prompts: Fine-tuned for translation (not general chat), reducing hallucinations
- Locale rules: Built-in Dutch, German, French rules for formatting, tone, and conventions
- Consistent format: Google Translate v2 API, no prompt engineering needed
- HTML preservation: Reliable tag handling, unlike raw GPT-4 which often breaks markup
- Completeness checks: Automated verification that nothing is omitted or added
- 7-day caching: Repeated content isn't re-translated (or re-billed)
When to use DeepL instead
DeepL still wins in specific scenarios:
- Ultra-low latency: DeepL responds in ~200ms vs ~500ms for Langbly
- 100% deterministic output: Same input always produces same output
- German literary translation: DeepL's German is exceptionally polished for formal texts
- Zero hallucination tolerance: Medical, legal, or safety-critical content
For everything else (especially Dutch, context-dependent content, and cost-sensitive workloads), Langbly delivers better results at a fraction of the cost.
Frequently asked questions
Is GPT-4 better than DeepL for translation?
For context-dependent content, idioms, and creative text: yes. GPT-4 understands meaning better. For simple, factual content: DeepL is faster and more consistent. Langbly gives you advanced AI quality with NMT-like reliability.
Why not just use GPT-4 directly for translation?
Three reasons: (1) Cost: GPT-4o costs ~$7.50/M chars, while Langbly plans range from $19/mo (5M chars, $3.80/M) to $199/mo (100M chars, $1.99/M), (2) Reliability: GPT-4 can hallucinate, omit text, or break HTML tags, (3) Convenience: you need prompt engineering and output parsing. Langbly handles all of this with a simple API.
Does Langbly use GPT-4?
Langbly uses optimized AI models selected for the best translation quality-to-cost ratio. The specific model may change as better options become available, but the API and quality remain consistent.
What about hallucinations in AI translation?
Langbly mitigates hallucination risk through optimized translation-specific prompts, completeness verification, and temperature=0 settings. Our eval system continuously monitors for added or omitted content across 160+ test cases.