> ## Documentation Index
> Fetch the complete documentation index at: https://developers.deepl.com/llms.txt
> Use this file to discover all available pages before exploring further.
# New: XML/HTML handling v2
> Learn about the benefits of tag handling v2 and how to migrate.
## Overview
Tag handling v2 is an improved algorithm for translating XML and HTML content. Set `tag_handling_version=v2` to enable it.
## What's New in v2
Tag handling v2 uses an algorithm that balances both translation quality and formatting. Sentences are now translated more naturally without being constrained by tag placement in the source text. It also handles edge cases around tag preservation, DOM hierarchy, and character escaping.
V2 enforces strict XML parsing and will return an error if invalid XML is submitted.
Customers who had not used tag handling prior to 2025-12-01 default to v2. All other customers default to v1.
## Usage Examples
### Translation with v2
```text Parameters theme={null}
tag_handling=html, tag_handling_version=v2
```
```markup Request theme={null}
Welcome to Our Service
This is a premium feature.
```
```markup Response theme={null}
Willkommen bei unserem Service
Dies ist eine Premium-Funktion.
```
```text Parameters theme={null}
tag_handling=xml, tag_handling_version=v2
```
```markup Request theme={null}
Press Continue to advance.
```
```markup Response theme={null}
Drücken Sie „Weiter", um fortzufahren.
```
```text Parameters theme={null}
tag_handling=xml, tag_handling_version=v2
```
```markup Request theme={null}
Please welcome the participants to today's meeting.
```
```markup Response theme={null}
Bitte begrüßen Sie die Teilnehmer an der heutigen Sitzung.
```
```text Parameters theme={null}
tag_handling=xml, tag_handling_version=v2
```
```markup Request theme={null}
The firm said it had been conducting an internal investigation for several months.
```
```markup Response theme={null}
Das Unternehmen gab an, dass es seit mehreren Monaten eine interne Untersuchung durchgeführt habe.
```
### Strict XML Parsing
Tag handling v2 enforces strict XML parsing. If invalid XML is submitted, the API will return an error:
```text Parameters theme={null}
tag_handling=xml, tag_handling_version=v2
```
```markup Request (Invalid XML) theme={null}
This tag is not closed properly
```
```json Response (Error) theme={null}
{
"Message": "Tag handling parsing failed, please check input."
}
```
Only XML is strictly parsed. HTML is not strictly parsed.
## Compatibility
Tag handling v2 is currently only compatible with the `quality_optimized` model type. Support for `latency_optimized` will be added in a future update.
| Model Type | v1 Support | v2 Support |
| ------------------- | :--------: | :--------: |
| `quality_optimized` | ✅ | ✅ |
| `latency_optimized` | ✅ | ❌ |
When you set `tag_handling_version` to `v2`, the `model_type` is implicitly set to `quality_optimized`.
Requests that specify both `model_type=latency_optimized` and `tag_handling_version=v2` will return an error.
## Migration Guide
Tag handling is expected to give different results between v1 and v2. Thoroughly test your system and verify any differences in output before switching to v2 in production.
### 1. Test Your Content
Run v2 translations on representative samples of your content, especially:
* Text with deep tag hierarchies
* Text with inline markup, attributes, and special characters
* Edge cases such as empty or self-closing tags
### 2. Compare Outputs
Compare v1 and v2 outputs, and make any updates needed to maintain your workflows.
* Ensure that the tags are preserved correctly
* Compare any differences in translation
* Note any formatting changes
### 3. Validate XML Syntax
Since v2 enforces strict XML parsing:
* Ensure all your XML input is well-formed
* Add error handling for invalid XML responses
* Update any XML generation logic if needed
## Related Documentation
For more information about XML and HTML tag handling:
* [HTML Handling](/docs/xml-and-html-handling/html)
* [XML Handling](/docs/xml-and-html-handling/xml)
* [Structured XML Content](/docs/xml-and-html-handling/structured-content)
## FAQ
**Q: What is the default tag handling version?**
A: Customers who had not used tag handling prior to 2025-12-01 default to v2. All other customers default to v1.
**Q: Should I upgrade to v2?**
A: Upgrading to v2 is strongly recommended and will provide improvements to both translation quality and structural correctness. Test thoroughly with your specific content before switching in production.
**Q: What happens if my XML is invalid?**
A: Tag handling v2 enforces strict XML parsing. Invalid XML will return an error response. Ensure your XML is well-formed before submission.
**Q: Can I switch back to v1 if needed?**
A: Yes, simply set `tag_handling_version: v1` in your API requests.
**Q: Does v2 work with all DeepL API features?**
A: Tag handling v2 works with all standard API features including glossaries and formality settings. However, it currently only supports the `quality_optimized` model type.
**Q: Is HTML also strictly parsed?**
A: No, any HTML can be submitted for translation without throwing an error. Only XML is strictly parsed and requires valid XML.