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Videos shot on an iPhone, especially in high resolutions like 4K, are often very large, with even short clips taking up hundreds of megabytes or more. This can quickly fill up storage space and make sharing difficult. In addition, most social platforms, such as WhatsApp, Discord, and email, impose strict file size limits on uploads, often capping videos at a few megabytes. This means large videos need to be compressed before they can be shared.

In this article, we’ll explain how to quickly compress videos on your iPhone using three methods: the built-in iPhone tools, iOS apps, and online video compressors.

Built-in iPhone Compression Tool

As far as I know, iPhones do not have a built-in tool specifically designed for video compression. The only option available is to trim the video into shorter clips using the Photos app. While this reduces the file size, it’s not a practical solution for most cases where the entire video needs to be preserved.

Third-Party Apps

You can install third-party apps from the App Store that offer video compression functionality. Some popular options include:

These apps generally deliver good compression results, but there are some downsides:

Cost: Most of these apps are either free trials or paid, meaning you’ll eventually need to pay. Some even require a 5-star review to unlock certain features, which feels unprofessional.
Convenience and Security: Installing an app can be inconvenient, and many are developed by small companies or individuals, which may raise concerns about data security.

Online Video Compressor

Online video compression through a browser is a popular and convenient choice for reducing video sizes without installing additional software. These tools fall into two categories:

1. Upload, Compress, and Download

With this method, you upload your video to a server, the server compresses it, and you download the compressed file. While effective, it has some drawbacks:

Time-Consuming: Uploading and downloading large videos can take a long time, especially with slower internet connections.
Costly for Mobile Devices: Data transfer can consume a significant amount of mobile data.
Privacy Concerns: Sharing private videos to external servers may pose security risks.

A reliable option in this category is Freeconvert.com. It supports videos up to 1 GB for free and offers fast compression with good quality.

2. In-Browser Compression

This method performs the compression directly within your browser, without uploading the video to a server. It has several advantages:

• Faster for Large Files: Avoids the need to upload or download, which saves time.

• More Secure: Videos remain on your device, reducing privacy concerns.

In-browser compression can be slower due to the limitations of browser-based tools but supports larger file sizes, often up to 2 GB.

Redpandacompress.com: A great choice for this category, offering secure and efficient compression for videos up to 2 GB. It also provides an automated size calculation tool for you to know the right size for your video. Learn how large should a 5 minute HD video be.

Both types of online compressors have their pros and cons, and the best choice depends on your priorities—speed, security, or file size limits.

Find the Best Method for Your Needs

Choosing the right method depends on your priorities. If you value speed and ease, third-party apps or server-based online tools might be the way to go. For those concerned about privacy and handling larger files, browser-based options like Redpandacompress.com are excellent choices.

Video size is often illusive and random to most people. Large, long HD films may only be several hundred MB, while a quick, daily-shot video from your phone could also be several hundred MB. This unpredictability is compounded by the common belief that reducing video size inevitably lowers the quality, which can make things even more confusing.

In this article, I’ll explain what’s behind the video size myth and help you understand how large a video should be, giving you more clarity the right size for your HD 5 minute video.

What is a Video and What is Video Compression?

A video is essentially a sequence of images, often referred to as frames, that are displayed rapidly in succession to create the illusion of motion. Depending on the video’s frame rate (fps), these images are shown at a rate of 30 frames per second (fps) or higher. This means that for every second of video, there are 30 individual images playing in quick succession.

Now, imagine trying to store all of these frames in their raw form. Let’s break it down with a simple example:

One 1080p Image	One Second of 1080p Video ( 30 fps )	One Minute of 1080p Video ( 60 seconds )
1MB	30MB	1,800MB ( 1.8GB)

Clearly, storing video in this raw format would be incredibly inefficient and take up a huge amount of storage space. Fortunately, there’s a more efficient way to store video: compression.

Video Compression

The key to making videos smaller lies in recognizing the similarities between consecutive frames. In most cases, the images from one frame to the next are very similar. For example, if you’re watching a video of someone walking, their body position will be slightly different from one frame to the next, but the background and most of the image will remain the same.

To capitalize on this, video compression techniques store only the differences between consecutive frames rather than storing each frame in full. In simple terms, only one full image among few seconds is saved, and the following frames only store the changes or differences from those full images. This technique is known as video compression.

What are the Factors that Affect the Video Size

Video Codec

While the concept of video compression sounds simple, the real challenge lies in identifying these similarities. This task is the job of video engineers who design compression algorithms, which is what we know as video codecs. These are the algorithms that figure out how to compress the video by detecting similarities between frames. Common codecs include H.264, HEVC (H.265), VP8, and VP9.

When you watch or upload a video, these codecs are typically packed into formats like MP4. Most of the time, you don’t need to worry about which codec is being used. However, newer codecs tend to offer better compression ratios. For example, HEVC (which is newer than H.264) can compress video more efficiently while preserving higher quality.

Video Content and Scene Complexity

Aside from the algorithm used, the content of the video itself plays a huge role in determining its file size. Here’s why:

• Still Images / Low Motion: In videos where very little is moving (like a still image with minimal changes between frames), the compression algorithm can achieve a very high compression ratio. This allows it to reduce the file size significantly without losing much quality.

• Rapid Movement / Complex Scenes: On the flip side, videos with rapid movement or complex scenes (like sports footage) present a challenge for compression. Since the frames differ greatly from one another, it’s harder for the algorithm to find similarities between them. As a result, the compression ratio will be lower. Further attempts to compress the video may reduce the image quality significantly.

Why Are iPhone Videos So Large?

If you’ve ever wondered why videos shot on your phone end up being so large? The answer lies in how your mobile device handles video encoding. Unlike professional video encoding softwares on computers, most smartphones (including iPhones) use hardware encoding that compress video at a constant bitrate. This means that, regardless of how much or little movement is in the video, the device applies a consistent level of compression across the entire video.

Hardware encoding doesn’t take full advantage of analyzing similarities between frames. It is designed because mobile devices usually lack the computational power to do such in-depth analysis on the fly. Consequently, videos from mobile devices may be larger than expected, and re-encoding or compressing the video later can often yield a much better file size with minimal quality loss. Read more about our blog upon how to compress a video on iPhone.

How Large a 5-Minute HD Video Should Be?

The truth is, the size of a 5-minute HD video can vary greatly. As much as it might sound unhelpful, the answer really is it depends. The file size is influenced by a number of factors:

1. The Video Codec: Different codecs offer different levels of compression. For example, HEVC (H.265) will compress the video more efficiently than H.264, which means you can expect a smaller file size with similar quality.

2. Motion and Similarity Between Frames: Videos with a lot of movement or changes from frame to frame will have a larger file size, as the compression algorithm will have a harder time finding similarities to reduce the data. On the other hand, static scenes with minimal movement will compress more effectively and yield a smaller file size.

3. Compression Methods: Not all compression methods are equal. If you don’t use the most efficient compression method for your video, you might end up with a file that’s much larger than it needs to be.

In that sense, some platforms provide general guidelines for video sizes:

	Netflix	Youtube
Bitrate Suggests	5Mbps-7Mbps	8Mbps-12Mbps
HD 5min Video Size Based on Bitrate	~225MB	~375MB
Reference	Link	Link

However, these guidelines don’t necessarily apply to your specific video. Your video’s content, motion, and codec choice will all affect the final file size.

You could also find a handy way to estimate your video size here:

Redpandacompress’s Automated Compression

To make things easier, Redpandacompress provides an automated compression tool that analyzes your video specifically and determines the most suitable compression settings. This ensures that you get the best possible size without compromising on quality. If you’re wondering how large your 5-minute HD video should be, give it a try here: Redpandacompress.com.

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How to Compress a Video on iPhone