---
title: "PSML"
source: https://dev.pageseeder.com/psml.html
description: "PSML is PageSeeder's markup language for representing document content and metadata. It uses structural, presentation, and metadata elements organized in XML format with .psml file extension."
last_updated: 2026-09-08T20:11:27+10:00
tokens: ~542
---

# PageSeeder Markup Language (PSML)

PSML is a markup language used by PageSeeder to represent document content and metadata.

The following is a simple PSML example:

```xml
<fragment id="2">
  <heading level="2">What's PSML?</heading>
  <para>PageSeeder's default markup language</para>
<fragment>
```

As PSML is natively supported, PageSeeder has tools to convert documents into PSML and to export PSML into other document formats.

In PageSeeder, a PSML document is represented as follows:

| icon | ![PSML icon](/content/images/psml/psml_icon.png) |
| --- | --- |
| file extension | `.psml` |
| mediatype | `application/vnd.pagaseeder.psml+xml` |

The PSML schema defines several types including:

- **Structural elements** like [\<section\>](psml/elements/element_section.md) and [\<fragment\>](psml/elements/element_fragment.md) are used to organize the various parts of the document.
- **Presentation elements**, such as [ \<para\> ](psml/elements/element_para.md)and [\<heading\>](psml/elements/element_heading.md), are similar to HTML and used for content markup. They are categorized into block-level and inline-level elements.
- **Metadata elements** such as [\<note\>](psml/elements/element_note.md) and [\<reversexrefs\>](psml/elements/element_reversexrefs.md) are used for annotations, references, versioning, and other document-related information, which are not intended to be displayed in the main presentation.

The [PSML element reference](psml/elements.md) provides an A-Z reference for every element used in PSML.

Some elements and attributes have specific data types. The [PSML datatypes](psml/datatypes.md) section offers an overview of the types used in PSML.

The [universal format](reference/glossary/universal_format.md) is a combination of conventions, file organization and packaging that allows an entire collection of linked PSML files to be safely moved from one server to another.

**Further reading**

For further technical information about PSML concepts and modeling, start with these [articles](guide/document_modeling.md).

Also see [restrictions](guide/document_modeling/restrictions.md) on PSML document size and content.