File types · Explainer

The OTP file (.otp)

An OTP file is an OpenDocument presentation template, the template format of LibreOffice Impress: opening it starts a new, untitled presentation with the template's master slides, styles and example slides. This guide explains what's inside one, how master slides make a template work, how OTP compares with ODP and PowerPoint's POTX, and has free sample OTP files to download for testing.

Sample OTP filesPut an OTP file online

At a glance

Full name
OpenDocument Presentation Template, part of the Open Document Format (ODF)
Extensions
.otp
MIME type
application/vnd.oasis.opendocument.presentation-template
Kind
Binary: a ZIP package of XML files and pictures, built exactly like an ODP
Standard
OASIS OpenDocument; ISO/IEC 26300
First released
2005, with ODF 1.0 and OpenOffice.org 2.0
Opens with
LibreOffice Impress, Apache OpenOffice Impress and other ODF presentation apps
Magic number
50 4B 03 04 (ZIP), then mimetype at byte 30 and application/vnd.oasis.opendocument.presentation-template at byte 38
The useful part
Master slides (style:master-page) and the presentation styles that go with them
Macros
Allowed under the same extension (LibreOffice Basic and other scripts)

The basics

What is an OTP file?

An OTP file is a template for LibreOffice Impress and other OpenDocument presentation apps. Company slide designs, lecture layouts and conference decks are shared as OTP files. Open one and Impress doesn't open the file itself: it creates a new presentation called Untitled 1 with a copy of the template's master slides, styles and slides, and the template stays as it was.

Inside, an OTP is built exactly like an ODP: XML files in a ZIP package, defined by the OpenDocument standard (OASIS, ISO/IEC 26300). It is the presentation member of the ODF template family, next to OTT for text and OTS for spreadsheets. PowerPoint's equivalent is the POTX.

What sets a presentation template apart is how much of it is design rather than content. A text template is mostly fixed text and fields; a presentation template is mostly master slides: backgrounds, colours, fonts, the position of the title and bullets, and footer elements, which every slide picks up.

Anatomy

What's inside an OTP file

Rename an .otp to .zip and it opens like any archive. Our sample-minimal.otp was written by hand with four entries: a master slide with a navy background in styles.xml, and one slide that uses it in content.xml.

sample-minimal.otp (file list and XML)
$ unzip -l sample-minimal.otp
  Length      Date    Time    Name
---------  ---------- -----   ----
       56  2026-10-27 12:00   mimetype
      495  2026-10-27 12:00   META-INF/manifest.xml
     1131  2026-10-27 12:00   styles.xml
     1723  2026-10-27 12:00   content.xml

Bytes 0-93: 50 4B 03 04 … "mimetype"
            "application/vnd.oasis.opendocument.presentation-template"

styles.xml (the master slide):
<style:page-layout style:name="PM1">
  <style:page-layout-properties fo:page-width="28cm" fo:page-height="15.75cm"/>
</style:page-layout>
<style:style style:name="Mdp1" style:family="drawing-page">
  <style:drawing-page-properties draw:fill="solid" draw:fill-color="#14213d"/>
</style:style>
<office:master-styles>
  <style:master-page style:name="Sample" style:page-layout-name="PM1"
      draw:style-name="Mdp1"/>
</office:master-styles>

content.xml (the one slide):
<office:presentation>
  <draw:page draw:name="Slide 1" draw:master-page-name="Sample">
    <draw:frame svg:x="2cm" svg:y="5cm" svg:width="24cm" svg:height="4.5cm">
      <draw:text-box>
        <text:p>Your title here</text:p>
        <text:p>Sample OTP from 99helpers.com/file-types/otp</text:p>
      </draw:text-box>
    </draw:frame>
  </draw:page>
</office:presentation>
  1. 150 4B 03 04

    The ZIP signature

    Every OTP is a ZIP file, like every ODP and POTX, so the first four bytes don't tell you what's inside.

  2. 2application/vnd.oasis.opendocument.presentation-template

    The template's type

    The mimetype entry comes first, uncompressed, so this 56-character string always starts at byte 38. An ODP has the 47-character …opendocument.presentation here.

  3. 3<style:page-layout>

    The slide size

    28 × 15.75 cm, Impress's default 16:9 size. Sizes are stored in real units, not pixels.

  4. 4style:family="drawing-page"

    The master's background

    A drawing-page style with a solid navy fill. Every slide built on this master gets the background unless it overrides it.

  5. 5<style:master-page style:name="Sample" …>

    The master slide

    What Impress calls a master slide or slide master. In a real template it also holds placeholders for the title and outline, footer fields and shapes such as logos.

  6. 6draw:master-page-name="Sample"

    A slide using the master

    Each draw:page names its master. Change the master and every slide that names it changes with it.

  7. 7<draw:frame>…<draw:text-box>

    Example content

    Text a template's user types over. A template's slides are ordinary slides; nothing marks them as examples.

Under the hood

What makes an OTP different from an ODP

We saved one Impress deck twice, as sample-template.otp and sample-template.odp, and compared the packages entry by entry. Only two entries differ:

EntryIn the OTPIn the ODP
mimetype…opendocument.presentation-template (56 bytes)…opendocument.presentation (47 bytes)
META-INF/manifest.xml, root entry…presentation-template…presentation
content.xml, styles.xml, meta.xml, settings.xml, thumbnailIdenticalIdentical

LibreOffice goes by that type, not the extension. In our tests with LibreOffice 24.2, the OTP renamed to .odp still opened as Untitled 1, and the ODP renamed to .otp opened as an ordinary presentation under its own name. To turn one into the other, save it again in the other format.

How it works

Master slides and presentation styles: the heart of an OTP

A master slide is a page in styles.xml that sits behind every slide built on it. Our sample-template.otp has two, and its three slides show both:

WhatSample Title masterSample Content master
BackgroundNavyPale grey-white
Shapes on the masterA blue band along the bottomA blue bar on the left
Title colourWhiteNavy
FooterNoneA text line and a slide number field
Used bySlides 1 and 3Slide 2
  • Presentation styles belong to a master. Each master gets its own set (title, subtitle, outline 1 to 9, notes, background), stored as styles named after it, such as Sample_20_Content-title. You can change them, but Impress doesn't let you create new ones.
  • Placeholders on the master set where a slide's title and bullets go. They're frames with presentation:class="title" or "outline" and presentation:placeholder="true".
  • Layouts (Title Slide, Title and Content, Title Only…) choose which placeholders a slide shows. The slide records its layout by name, such as AL2T1.
  • Fields on the master, such as the slide number in our content master, fill themselves in on every slide.

Apply a template's design to an existing deck

You don't have to start from the template. In Impress, select the slides, choose Slide, Change Slide Master, click Load, pick the template, then choose one of its masters. Tick Exchange background page to apply it to every slide.

In LibreOffice

Making and using presentation templates in Impress

  • Make a template: set up the master slides (View, Master Slide), then File, Templates, Save as Template, give it a name and pick a category. Or use File, Save As with the type ODF Presentation Template (.otp) and save it anywhere.
  • Use a template: File, New, Templates (or Ctrl+Shift+N), filter on Presentations and double-click one. Double-clicking an .otp in your file manager does the same.
  • Edit a template: in the Templates dialog, right-click it and choose Edit. Opening the .otp the normal way only gives you a new presentation.
  • Change the default: right-click a template and choose Set as Default. New presentations then start from it.
  • Add someone else's template: in the Templates dialog, choose Manage, Import, pick a category and the .otp file. Until then, it doesn't appear in the dialog.

Comparison

OTP vs POTX, POT and ODP

OTPPOTXPOTMPOTODP
What it isODF presentation templatePowerPoint templatePowerPoint template with macrosPowerPoint 97-2003 templateODF presentation
Native appLibreOffice ImpressMicrosoft PowerPointMicrosoft PowerPointPowerPoint 97-2003LibreOffice Impress
StructureZIP of XMLZIP of XMLZIP of XMLOLE2 binaryZIP of XML
Slides storedAll in content.xmlOne XML part per slideOne XML part per slideBinary recordsAll in content.xml
What marks a templatemimetype entryMain part content typeMain part content typeThe extension(not a template)
MacrosYes, same extensionNoYesYes, same extensionYes, same extension

Use OTP when the people using the template work in LibreOffice, and POTX when they work in PowerPoint. Masters convert, but themes, fonts and placeholder positions can shift: when we converted sample-template.otp to POTX with LibreOffice and back, both masters and all three slides came through, but test a converted template in the app that will use it.

How to

How to open and convert an OTP file

  • LibreOffice Impress (free; Windows, macOS, Linux) opens OTP files natively, as do Apache OpenOffice and other ODF presentation apps.
  • To a presentation: open the template (which creates Untitled 1) and save it as ODP or PPTX, or run soffice --headless --convert-to odp deck.otp.
  • To a PowerPoint template: File, Save As, PowerPoint 2007-365 Template (.potx), or soffice --headless --convert-to 'potx:Impress MS PowerPoint 2007 XML Template' deck.otp.
  • From a presentation or PowerPoint template: soffice --headless --convert-to 'otp:impress8_template' deck.potx (a PPTX or ODP works as input too).
  • PowerPoint and Google Slides work with ODP presentations. For a template, the dependable route is to create a presentation from it in LibreOffice and send that, or convert the template to POTX.
  • In a browser: browsers can't display OTP files, so a link to one downloads it.

Troubleshooting

Common OTP problems and how to fix them

  • Opening the template gives Untitled 1. That's how templates work. To change the template itself, use Edit in the Templates dialog.
  • I changed a slide's colour, but the others didn't follow. You edited the slide, not the master. Open View, Master Slide and make the change there.
  • The template's fonts look different on another computer. OTP files usually don't embed fonts, so a missing font is replaced. Use fonts installed everywhere, or tick Embed fonts in document under File, Properties, Font.
  • The template doesn't appear in the Templates dialog. It's not in a templates folder. Use Manage, Import, or Save as Template.
  • "The file is corrupt" after editing the ZIP by hand. The mimetype entry must be first and uncompressed. With Info-ZIP: zip -X0 new.otp mimetype then zip -Xr new.otp . -x mimetype.
  • It downloads as a ZIP or opens as the wrong type. The server sends application/zip. Serve .otp as application/vnd.oasis.opendocument.presentation-template.

Security

Is an OTP file safe to open?

Like ODP, an OTP has no separate macro-free extension: any .otp can contain LibreOffice Basic or other scripts, and presentations made from it carry them on. LibreOffice's default macro security only runs macros that are signed by a trusted source or stored in a trusted location. Don't lower it because a template asks you to.

  • Hidden content travels. Speaker notes, hidden slides and shapes on a master that are covered by other shapes are copied into every presentation made from the template. Check them before you present or share a deck outside your organisation.
  • Links and media. A template can link to pictures, sounds or videos outside the file instead of embedding them. Links break when the file moves, and a link to a web address lets that server see when the media is loaded.
  • Keep LibreOffice updated: templates are parsed by the same code as presentations.

Free downloads

Sample OTP files to download

Free sample OpenDocument presentation templates for testing uploads, file-type detection, converters and template handling. The template deck was built in LibreOffice Impress 24.2 and saved twice, as OTP and as ODP; the minimal file was written by hand. All were checked with unzip -t, odfpy and a LibreOffice export to PDF. None contains macros.

sample-template.otp · 29.6 KBDownload

Browsers can't show this kind of file in a page. Download it to open it in the app it belongs to.

What's inside sample-template.otp

Browsers can't preview OTP files, so download it and open it in LibreOffice Impress: you get Untitled 1, a new presentation based on it. These are the parts to look for.

  1. Two master slides

    View, Master Slide shows Sample Title (navy, a blue band along the bottom) and Sample Content (pale, a blue bar on the left). Both are style:master-page elements in styles.xml.

  2. Presentation styles per master

    Each master has its own title, subtitle and outline styles: white titles on the dark master, navy on the light one. Look for Sample_20_Title-title and Sample_20_Content-title.

  3. A footer with a slide number

    The content master has a text line and a slide number field, so slide 2 shows "Sample template · 99helpers.com/file-types/otp · 2".

  4. Three example slides

    A title slide and a closing slide on the dark master, and a bulleted content slide with two outline levels on the light master.

  5. Speaker notes

    Every slide has a note explaining what it shows, stored in a presentation:notes element inside the slide.

  6. Metadata and type

    Title "Sample presentation template" and the description "… Free sample from 99helpers.com/file-types/otp" in meta.xml; …presentation-template in the mimetype entry and the manifest.

All sample OTP files

  • Presentation template, two masters

    sample-template.otp · 29.6 KB (30,275 bytes)

    A 16:9 template with two master slides (dark title, light content), presentation styles for each, a footer with a slide number field, and three example slides with speaker notes.

    • Checking that an app creates a new presentation from a template
    • Testing how converters handle several master slides
    Download

  • The same deck as an ODP

    sample-template.odp · 29.6 KB (30,261 bytes)

    Saved from the same Impress document as the OTP. Only the mimetype entry and the manifest's root entry differ.

    • Comparing a template with a presentation
    • Testing code that must tell OTP from ODP
    Download

  • Minimal OTP, four entries

    sample-minimal.otp · 1.6 KB (1,633 bytes)

    Only mimetype, META-INF/manifest.xml, styles.xml with one master slide and content.xml with one slide, written by hand. It's the file shown in the anatomy above.

    • Parser tests: don't assume optional parts exist
    • Checking detection by the mimetype entry
    Download

Ways to test with them

  • File type detection: all three start with PK and have mimetype at byte 30. Read from byte 38: the two OTP files say …presentation-template, the ODP says …presentation followed by other data.
  • New file, not the template: opening sample-template.otp should give an untitled presentation. An app that saves over the template has a bug.
  • Masters in conversion: convert sample-template.otp to POTX or PPTX and check there are still two slide masters, and that slide 2 keeps its blue bar and slide number.
  • Apply a design: in Impress, open any deck, then Slide, Change Slide Master, Load, and pick sample-template.otp. Both masters should be offered.
  • Defensive parsing: sample-minimal.otp has no meta.xml, settings.xml or thumbnail. Code that assumes they exist will fail on it.

Free to use for testing, teaching and demos, commercially or not, with no attribution needed. A link back to this page is always appreciated.

Put it online

Have an OTP file? Give it a link.

Drop a LibreOffice presentation template on 99helpers and it gets its own link, ready to share with your team. Browsers can't display OTP files, so visitors download it and open it in LibreOffice Impress, which starts a new presentation from it.

Put an OTP file online

Questions

OTP files, frequently asked

What is an OTP file?

An OpenDocument presentation template, the template format of LibreOffice Impress. Opening it creates a new, untitled presentation with the template's master slides, styles and example slides.

What's the difference between OTP and ODP?

Inside, only the type in the mimetype entry and the manifest: …presentation-template instead of …presentation. In use, an ODP opens itself, while an OTP starts a new presentation.

How do I open an OTP file?

With LibreOffice Impress or another ODF presentation app such as Apache OpenOffice. Double-clicking it creates a new presentation from it.

How do I edit an OTP template?

In LibreOffice, open File, Templates, Manage Templates, right-click the template and choose Edit. Change the design under View, Master Slide, then save.

Can PowerPoint open OTP files?

PowerPoint works with ODP presentations. For a template, convert it in LibreOffice to POTX, or create a presentation from it and save that as PPTX.

How do I apply an OTP template to an existing presentation?

In Impress, choose Slide, Change Slide Master, click Load, pick the template and then one of its master slides. Tick Exchange background page to apply it to all slides.

How do I convert an OTP to POTX?

In LibreOffice, save it as PowerPoint 2007-365 Template (.potx). On a server: soffice --headless --convert-to potx file.otp.

Can an OTP file contain macros?

Yes. OTP has no separate macro-free extension. LibreOffice blocks unsigned macros by default; keep that setting for templates you didn't make.

Related formats

Other file types explained

ODP filePOTX filePOT filePOTM filePPTX fileOTT fileOTS fileAll file types

Keep going

Related

Host an OTP file

Put a LibreOffice presentation template online at its own address.

Share an OTP file

Send a template as a link instead of an attachment.

Host a presentation

Publish the finished deck people can open from a link.

Sources

Last reviewed 27 October 2026.