How to compress a video

Online tools are a good choice for fast, uncomplicated compression without installation. Be sure to adjust the resolution, codec (H.264), and bit rate to effectively reduce the file size.

• Upload your video to the website. Select the desired output format (e.g., MP4) and compression options, if necessary.
• Start the compression and download the reduced video. This method is fast and requires no installation, but is more suitable for smaller files and if you do not have sensitive content.
• CapCut offers fast compression, many formats and editing functions, is cloud-based, and delivers high-quality output.
• FreeConvert has high compression rates, batch processing, many formats, and good data protection.
• VideoSmaller is very easy to use, offers lossless compression, and does not require registration.
• Flixier offers real-time collaboration, a cloud platform, and fast processing.
• The interface at Clideo is intuitive, compression is fast, and sharing is easy.
• Ezgif does not embed watermarks, has many editing features, and is easy to use.
• AConvert also compresses documents and is easy to use.
• Zamzar offers simple conversion/compression and drag-and-drop functionality.
• FlexClip is intuitive to use. It offers numerous templates and a real-time preview.
• HDconvert delivers high-quality output, customizable settings, and audio optimizations.

The quality of the video has a direct impact on the file size after compression. The higher the desired quality after compression, the larger the file will be. If the quality is reduced more significantly—for example, by lowering the bitrate or resolution—the file size will be smaller, but at the expense of image sharpness and detail.

• A higher bitrate means better image quality, but also larger files. Reducing the bitrate decreases the file size, but also reduces the quality.
• Videos with higher resolution (e.g., 1080p or 4K) are significantly larger than videos with lower resolution (e.g., 720p or 480p). Reducing the resolution reduces the file size, but also reduces image detail.
• Lossy compression permanently removes data from the video, which leads to a loss of quality but significantly reduces the file size. Lossless compression preserves quality but cannot reduce the file size as much.
• A lower frame rate reduces the file size but can make the video appear less smooth.
• The more you compress a video, the more quality is lost and the smaller the file becomes. Modern codecs can minimize the losses, but complete compression without quality loss is usually not possible. The optimal balance between quality and file size depends on the intended use and the requirements for the video.

New compression formats such as H.265/HEVC offer numerous advantages over older standards such as H.264:

• Significantly higher compression efficiency: H.265/HEVC can compress video files at approximately half the bit rate of H.264 while maintaining the same image quality. This means that videos require less storage space and can be transferred more quickly without compromising quality.
• Support for high resolutions: H.265 has been specially developed for modern requirements such as 4K and 8K videos. This makes the codec ideal for Ultra HD content and future video standards.
• Lower bandwidth requirements: Thanks to more efficient compression, less bandwidth is required for streaming or transferring videos. This enables smooth streaming.
• Improved image quality: H.265 uses more advanced algorithms for image prediction and motion analysis. This keeps image quality high even at low bitrates and minimizes artifacts. The quality advantage is particularly noticeable in complex or fast-moving scenes.
• Reduced storage requirements: Better compression significantly reduces the storage requirements for video files. This is particularly advantageous for large video archives, surveillance systems, or mobile devices with limited storage space.
• Flexibility and future-proofing: H.265 is suitable for a wide range of applications and devices, from smartphones and streaming platforms to professional video surveillance systems. It is an important building block for the transmission and storage of UHD content.

The use of online video compression services entails data protection risks. For private purposes, local tools should be used whenever possible. In a business environment, it is essential to carefully select and review services for GDPR compliance and security.

• Basic data protection risks: When uploading videos to online services, personal data (e.g., people visible in the video, metadata such as location, IP address) is often also transferred to the provider. This data can be viewed or further processed by third parties, especially if the service is operated outside the EU.
• Many online services store uploaded videos on their servers, at least temporarily. There is a risk that this data will be used for analysis, advertising, or tracking purposes. Users often do not know how long their data will be stored or for what purpose. Deletion after use is also not always guaranteed.
• Requirements under the GDPR: Services that process personal data must inform users transparently about the nature and purpose of the processing and, if necessary, obtain consent. Only data necessary for compression may be processed. If an external service provider is commissioned, a contract for order processing (AVV) must be concluded in accordance with Art. 28 GDPR, especially for commercial use. If processing takes place outside the EU, additional protective measures (e.g., standard contractual clauses) must be taken.
• Security aspects: Make sure that the service uses HTTPS to secure the transmission of video data. Reputable services automatically delete uploaded videos after compression or offer a manual deletion option. Privacy-first providers do not use cookies, tracking, or profiling. This means that no user profiles are created and no data is passed on to third parties. With professional solutions, videos can be delivered via your own domain, so that no data flows to third-party providers.
• Recommendations for safe use: Use services that explicitly advertise data protection and GDPR compliance, or open-source tools that run locally on your own computer. When embedding videos on websites, the use of external services must be indicated in the privacy policy. For third-party providers such as YouTube, the “extended privacy mode” is recommended and a two-click solution is advisable. Refrain from compressing particularly sensitive or confidential videos via online services.

There are different requirements and best practices for optimally adapting videos to different platforms such as YouTube, WhatsApp, and email. Here are some practical tips for each platform:

• YouTube: YouTube recommends uploading in at least 1080p (Full HD), ideally in MP4 format (H.264 codec, AAC audio). The standard aspect ratio is 16:9. YouTube accepts large files, but for faster uploads, compression without significant loss of quality is recommended.
• Create an appealing thumbnail (1280×720 pixels) to get more clicks. Optimize it for search engines and the YouTube algorithm to increase your reach. Break up longer videos with chapters and offer subtitles to increase accessibility. Use these features to draw attention to other videos or channels.
• WhatsApp: Select a maximum file size of 16 MB for direct sending and 30 seconds for status videos. WhatsApp compresses videos to 720p to 1080p, even if you record in 4K. Compress videos yourself in advance to maintain control over the quality. The ideal aspect ratio is 9:16 (portrait) for status, otherwise flexible.
• Use apps such as InShot, HitPaw Univd, PowerDirector, or VLC Media Player to reduce the file size. Use splitter apps to automatically divide longer clips into 30-second segments. Add stickers, text, or filters directly in WhatsApp to personalize the video.
• Email: The maximum file size is usually 20 to 25 MB per attachment, depending on the provider. Don’t attach large videos directly, but share them via a cloud link (e.g., Google Drive, Dropbox). Create a preview image (thumbnail) with a play button and link it to the video in the cloud or on YouTube.
• For smaller videos, it is best to use compression tools to reduce the file size without losing too much quality. MP4 is the most compatible format for most devices and email clients.