A CDR file is a recording of what happened on your screen during a specific time period

CDR stands for "Camtasia Disk Recording." It is a video file format created by Camtasia, a screen recording and video editing program made by TechSmith. When you use Camtasia to record your screen — whether you are capturing a tutorial, a presentation, or a software demonstration — the program saves that recording as a CDR file on your computer.

The CDR format is proprietary, meaning only Camtasia can open and edit these files directly. If you record a 10-minute screen capture in Camtasia, you get a CDR file that contains all the video, audio, and editing information from that session. Think of it as the "working file" — similar to how a Word document is the working file for text, or a Photoshop PSD file is the working file for images.

CDR files are larger than finished video files because they store extra information that Camtasia needs to let you edit the recording later. Once you are done editing and want to share the video, you export it to a standard format like MP4 or MOV, which most devices and websites can play.

Key Takeaways

  • CDR files are screen recordings created by Camtasia, a program designed for making tutorials and video demonstrations.
  • Only Camtasia can open and edit CDR files directly — they are not a universal video format.
  • CDR files are larger than finished videos because they contain editing information and multiple layers of content.
  • When you finish editing a CDR file, you export it to MP4, MOV, or another common format so other people can watch it.
  • You will encounter CDR files only if you or someone you work with uses Camtasia to record screen activity.

How CDR files differ from other video formats

Most video files you encounter — MP4, MOV, AVI — are finished products. They contain the video and audio compressed into a single playable file. Your phone, your web browser, and your media player can all open these formats without any special software.

A CDR file is different because it is a project file, not a finished file. It stores the raw recording along with all the edits, annotations, zooms, and effects you added in Camtasia. If you recorded your screen for 15 minutes but only want to use 5 minutes of it, the CDR file remembers which 5 minutes you selected and how you trimmed it — but the full 15 minutes is still stored inside. This is why CDR files take up so much space.

Other programs have similar project files: Adobe Premiere uses PRPROJ files for video editing, Final Cut Pro uses FCPXML files, and DaVinci Resolve uses DRP files. All of these are "working files" that let you edit and refine your content before you export to a shareable format.

When you might encounter a CDR file

You will run into CDR files if you work in training, education, or content creation. Instructors who record lectures often use Camtasia because it is straightforward and includes built-in tools for adding captions, highlighting, and zoom effects. If a colleague sends you a CDR file, they are usually asking you to edit it or review it before it gets exported to a final video.

Software companies also use Camtasia to create product tutorials and onboarding videos. If you read a tutorial package from a vendor and find a CDR file inside, it means the company is sharing the editable version so you can customize it for your own needs — perhaps by adding your company logo or changing the narration.

If you find a CDR file on your computer and you did not create it, someone else on your device or network probably used Camtasia to record something. Check your Downloads folder or look at the file's creation date to figure out when it was made.

What to do if you receive a CDR file

If someone sends you a CDR file and you need to watch it, you have three options. The simplest is to ask the sender to export it to MP4 or another common format — most people who create CDR files can do this in seconds. If you need to edit the file yourself, you will need to install Camtasia, which is a paid program with a free trial period.

If you want to convert a CDR file without Camtasia, some third-party video conversion tools claim to handle the format, but results are often poor because they cannot read all the editing information inside the file. Your best bet is still to ask the person who created it to export it properly.

If you have a CDR file you no longer need, you can safely delete it like any other file. Deleting a CDR file does not affect anything else on your computer — it is just a data file, not a system file.

How to open a CDR file

To open a CDR file, you need Camtasia installed on your computer. You can read Camtasia from TechSmith's website for Windows or Mac. The program offers a free trial that lasts 30 days, so you can test it before deciding whether to buy it.

Once Camtasia is installed, opening a CDR file is straightforward: launch Camtasia, go to File > Open, and select your CDR file. The recording will load into the editor, and you can play it, trim it, add effects, or make any other changes you want.

Camtasia also lets you export your finished video to multiple formats. After you are done editing, go to File > Export and choose your format — MP4 is the most common choice because it works on almost any device and website. You can adjust the video quality and file size during export, which is useful if you need a smaller file for email or a higher-quality file for professional use.

Storage and file size considerations

CDR files are typically large — a 10-minute screen recording can easily be 500 MB to 2 GB depending on your screen resolution and frame rate. If you record at 4K resolution or at 60 frames per second, the file will be even larger. This matters if you are storing files on a laptop with limited space or trying to back them up to cloud storage.

If you have old CDR files you want to keep but do not need to edit anymore, export them to MP4 and delete the CDR version. An MP4 export of the same 10-minute recording might be only 100 to 300 MB, saving you significant space. Keep the CDR file only if you think you will need to edit it again in the future.

When backing up your computer, CDR files will be included automatically if you back up your entire drive or your Documents folder. If you use cloud storage like OneDrive or Google Drive, be aware that large CDR files will count against your storage limit, so you may want to store them locally instead.

Frequently Asked Questions

Can I play a CDR file in Windows Media Player or VLC?

No. Windows Media Player and VLC cannot open CDR files because they are proprietary to Camtasia. You need Camtasia itself to open and play a CDR file. If you want to watch the video without Camtasia, ask whoever created it to export it to MP4 or another standard format.

Is a CDR file the same as a video file?

Not exactly. A CDR file contains video, but it also contains editing information, layers, and effects that a standard video file does not. Think of it as a video plus instructions — a standard video file is just the final result. You export a CDR file to create a standard video file.

Why is my CDR file so large?

CDR files store the complete uncompressed recording plus all the editing data. A 10-minute screen recording at high resolution can easily be 1 to 2 GB. Once you export it to MP4, the file will be much smaller because the video is compressed and the editing information is no longer needed.

Can I delete a CDR file after I export it?

Yes. Once you export a CDR file to MP4 or another format, you can safely delete the CDR file if you do not plan to edit it again. The exported video is a complete, independent file that does not depend on the CDR file existing.

What if I need to edit a CDR file but cannot afford Camtasia?

You can use Camtasia's free 30-day trial to edit and export your file. If you need longer access, TechSmith offers educational discounts for students and teachers. Alternatively, ask the person who created the CDR file to make the edits you need and send you the exported video instead.