MP4 vs MOV vs WebM vs AVI vs MKV: Which Video Format Should You Use?

Use MP4 with H.264 codec for maximum compatibility - it plays on virtually every device made since 2010. Use MOV with ProRes for professional video editing (high quality, fast editing). Use MKV for personal media libraries (supports multiple audio tracks, subtitles, chapters). WebM is primarily for web delivery with modern browsers. Avoid AVI for modern use.

The key distinction is container vs codec: the container (MP4, MOV, MKV) is the file format, while the codec (H.264, H.265, ProRes) determines how video is compressed. The same codec can go in different containers, and compatibility depends on both.

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I spent four days re-encoding 200 family videos because I chose the wrong format. The videos wouldn't play on my parents' TV, my sister's iPad, or my brother's gaming console. Each device gave a different cryptic error message. I thought the problem was the devices. It wasn't. The problem was my overconfident choice of video format.

Those four days taught me more about video formats than any technical article ever could. This guide contains the practical knowledge I wish I'd had before wasting nearly a week of my life fixing a problem I'd created for myself.

The Family Video Disaster

Last year, I digitized decades of family videos from old tapes. I spent weeks carefully converting VHS, Mini DV, and camcorder tapes to digital files. I researched obsessively to find the "best" video format that would preserve quality for future generations.

I discovered that MOV with ProRes codec offered the highest quality. Technical forums praised it. Professional editors swore by it. I converted all 200 videos to MOV with ProRes 422, creating pristine digital archives.

The files were massive - about 50 GB per hour of video - but I didn't care. Quality mattered more than storage. I bought a 4 TB external drive and filled it with these perfectly preserved family memories.

Then I brought the drive to my parents' house for a family viewing. I plugged it into their smart TV. Nothing. The TV saw the files but wouldn't play them. I tried my sister's iPad. Same result. I tried my brother's PlayStation. Nope.

Out of 200 carefully converted videos, not a single one would play on any of their devices. Only my Mac laptop could play them because macOS natively supports ProRes MOV files.

I'd chosen a format that offered maximum quality but minimum compatibility. For archival masters, that's fine. For sharing with family who just want to watch videos on their normal devices, it was catastrophic.

I spent the next four days reconverting everything to MP4 with H.264. Every single file. The MP4 versions played flawlessly on every device we tried. That's when I learned that "best" format depends entirely on your actual use case.

What Is the Difference Between a Video Container and Codec?

The confusion around video formats comes from conflicting terminology. When I researched formats, some articles talked about containers, others discussed codecs, and I initially thought they were the same thing. They're not.

Container vs Codec: The Lunchbox Analogy

A container (MP4, MOV, MKV, AVI) is like a lunchbox. It's the file format that holds the video.

A codec (H.264, H.265, ProRes, VP9) is what's inside the lunchbox - it's how the video is actually compressed and stored.

This distinction is crucial because:

• The same codec can go in different containers
• The same container can hold different codecs
• Compatibility depends on both the container and the codec

When my MOV files wouldn't play, the problem wasn't the MOV container itself - it was the ProRes codec inside. The devices could handle MOV containers but didn't support ProRes codec.

Why This Matters Practically

Two files named "video.mp4" might be completely different:

• One could be MP4 container with H.264 codec (plays everywhere)
• Another could be MP4 container with H.265 codec (plays on newer devices only)

The container tells you less than you'd think about compatibility. The codec inside determines whether your video actually plays.

Why Is MP4 the Best Video Format for Most People?

After my format disaster, I switched almost everything to MP4 with H.264 codec. Not because it's technically superior, but because it just works.

Why MP4 Dominates

MP4 became the default for reasons that have nothing to do with being "best" technically. It won through ubiquity and compatibility, not superiority.

Every device I've tested plays MP4 with H.264:

• Smart TVs from 2010 onward
• All smartphones and tablets
• Game consoles (PlayStation, Xbox, Switch)
• Streaming devices (Roku, Chromecast, Apple TV)
• Web browsers on desktop and mobile

I've never encountered a modern device that can't play MP4 with H.264. It's the linguistic equivalent of English - not necessarily the best language, but the one everyone understands.

When I Use MP4

I default to MP4 for nearly everything:

Family videos: After my disaster, all family content is MP4. Everyone can watch on their preferred device.

YouTube uploads: YouTube accepts other formats but immediately transcodes them to their preferred codecs anyway. Starting with MP4 saves processing time.

Client deliverables: When clients say "send me the video," they mean MP4. Even if they don't know they mean MP4.

Social media: Instagram, Facebook, TikTok all accept other formats but work best with MP4.

Archival (shared copies): I keep master files in other formats, but the version I share with family is always MP4.

Should I Use H.264 or H.265 Codec?

Inside that MP4 container, you're usually choosing between H.264 and H.265 codecs.

H.264 is older (from 2003) but universally supported. Every device plays it without thinking. File sizes are reasonable. Nobody complains.

H.265 is newer (from 2013) and more efficient. For the same quality, files are about 40-50% smaller. That sounds great until you realize many devices still struggle with it.

I tested this extensively:

• My 2022 iPhone: plays H.265 perfectly
• My parents' 2019 smart TV: stutters with H.265, smooth with H.264
• My car's entertainment system: won't play H.265 at all
• My sister's 2018 iPad: drains battery rapidly with H.265

I now use H.264 by default. When everyone's devices handle H.265 smoothly (maybe in another 2-3 years), I'll reconsider. But today, the compatibility hassles outweigh the file size savings.

When Should I Use MOV Format?

MOV works beautifully within the Apple ecosystem. The problems start when you leave that ecosystem, which is exactly what I learned the hard way.

When MOV Makes Sense

MOV isn't inherently bad. It's just specialized.

I use MOV with ProRes for:

Editing masters: My video editor handles ProRes beautifully. Editing is smooth, rendering is fast, quality remains pristine through multiple generations of edits.

Archival originals: For family videos, I keep MOV ProRes masters and MP4 H.264 distribution copies. The ProRes masters are for preservation, the MP4 copies are for viewing.

Professional delivery: When delivering to other video professionals who explicitly request ProRes, MOV is appropriate.

But I learned to never assume MOV is appropriate for general sharing.

The ProRes Trap

ProRes is a professional codec that offers:

• Minimal quality loss through multiple editing generations
• Fast encoding and decoding
• High bit-depth color
• Features that matter for professional production

But it creates huge files (50+ GB per hour) and requires specific software support. It's a production format, not a distribution format.

My workflow now:

1. Keep editing masters in MOV with ProRes
2. Export finished videos to MP4 with H.264 for sharing
3. Archive both the ProRes master and the MP4 distribution copy

The Codec Confusion

MOV containers can hold many different codecs. When someone says "MOV file," that doesn't tell you much about compatibility. You need to know what's inside.

I received a MOV file from a colleague that wouldn't play on my Mac - confusing since macOS natively supports MOV. Turned out it contained an obscure codec my system didn't have. The MOV container was fine. The codec inside was the problem.

WebM: The Format Google Wants You to Use

WebM is Google's open-source video format. It's royalty-free, which matters to Google but usually doesn't matter to individuals.

Why YouTube Uses WebM (Even If You Upload MP4)

I discovered by accident that YouTube converts all uploads to WebM (with VP9 codec) on their backend. I uploaded MP4, but when I inspected the served video, YouTube was delivering WebM to most viewers.

YouTube does this for bandwidth efficiency. Serving billions of videos daily, they save money by using the most efficient compression. For their use case, WebM makes perfect sense.

For my use case as a creator, MP4 still makes more sense because:

• My editing software handles MP4 better
• My clients can't always play WebM files
• The compatibility range of MP4 is wider

When I Actually Use WebM

Honestly, rarely. I've used WebM in exactly two situations:

Website background videos: I built a site that needed looping background video. WebM's smaller file size meant faster loading. For this specific use case, it was perfect.

Experimental projects: When I'm not worried about compatibility because I control the playback environment, WebM's efficiency is appealing.

For everything else, the compatibility hassles aren't worth the marginal file size savings.

Browser Support Reality

Modern web browsers support WebM, but that's different from saying all video players support it. I can embed WebM on a website and it plays in browsers. But if I send someone a WebM file to download and watch locally, they might not have software that plays it.

MP4 plays in browsers AND in local players. WebM usually only plays in browsers or specialized software.

MKV: The Format for Enthusiasts

MKV is the Swiss Army knife of video containers. It supports virtually any codec, unlimited audio tracks, multiple subtitle languages, chapter markers, and extensive metadata. It's beloved by media enthusiasts and ignored by average users.

Why I Have 200 MKV Files

My personal movie collection is mostly MKV files. Each file contains:

• The video in H.265 for quality and file size
• Multiple audio tracks (English, directors' commentary, descriptive audio)
• Subtitle files in multiple languages
• Chapter markers for easy navigation

For my home media server running Plex, MKV is perfect. I have one file that contains everything I might want.

The Compatibility Problem

I brought my media server to a friend's house for a movie night. Her TV, which was only two years old, simply said "format not supported" for every MKV file. We ended up using Netflix instead.

MKV files require capable media players. Many smart TVs, especially older ones, don't support MKV. Game consoles are hit-or-miss. Mobile devices usually need specific apps.

If you're tech-savvy and control the playback environment, MKV is great. If you're sharing with random people who expect files to "just work," MKV creates support headaches.

My MKV Workflow

For personal archives: MKV with H.265, multiple audio tracks, chapters, and subtitles.

For sharing with others: Convert to MP4 with H.264 before sending.

This dual-format approach gives me the features I want for personal use while maintaining compatibility for sharing.

AVI: The Format from 1992 That Won't Die

AVI is ancient. Microsoft created it in 1992. It has limitations that were reasonable then and are absurd now. Yet I still encounter AVI files regularly.

Why AVI Still Exists

Legacy. Some old screen recording software defaults to AVI. Some security cameras from the 2000s only export AVI. Some government organizations have workflows built around AVI that nobody wants to update.

I received training videos from a corporate client in AVI format. The videos were recorded in 2022 but exported to a format from 1992. When I asked why, they said "that's what our screen recording software uses by default and nobody knows how to change it."

What I Do With AVI Files

Immediately convert them to MP4. I've never found a reason to keep anything in AVI format for modern use.

The one exception: working with ancient software that specifically requires AVI input. But even then, I check if there's an updated version first.

How Do I Choose the Right Video Format?

After years of trial and error, I've developed a simple decision process.

Question 1: Who needs to watch this?

If anyone outside your immediate control: → Use MP4 with H.264. Don't even consider other options.

This includes:

• Family members
• Clients
• Social media uploads
• Anything going on a website
• Files you're sending to "normal" people

If only you or technical collaborators: → Consider other formats based on specific needs.

Question 2: Is this for editing or distribution?

For editing (the working file you'll edit multiple times): → MOV with ProRes if you have good hardware and fast storage → MP4 with H.264 if storage is limited or hardware is modest

For distribution (the finished file people will watch): → MP4 with H.264 always

Question 3: Do you need special features?

Multiple audio tracks, extensive subtitles, chapter markers: → MKV if you control the playback environment → Otherwise, use MP4 and provide separate subtitle files

Maximum quality for archival: → MOV with ProRes for masters → Also create MP4 distribution copies

Smallest file size: → MP4 with H.265, but test playback on target devices first → If devices don't support H.265, use H.264

Question 4: When in doubt?

Default to MP4 with H.264.

It's the boring, safe choice that almost never causes problems.

Real File Size Comparisons

I encoded the same 10-minute 1080p video in different formats to see actual file sizes:

MOV with ProRes 422: 8.2 GB MP4 with H.264 (high quality): 420 MB MP4 with H.265 (same quality): 240 MB WebM with VP9 (similar quality): 210 MB MKV with H.265 (same quality): 245 MB

Observations:

• ProRes is 20x larger than H.264 for similar visual quality
• H.265 saves about 40% compared to H.264
• WebM is slightly more efficient than H.265
• Container choice (MP4 vs MKV) barely affects file size - the codec matters

For distribution, the difference between MP4 H.264, MP4 H.265, and WebM is measured in tens of megabytes. For my 10-minute video, we're talking about a 200 MB difference.

Over slow internet, that matters. For storage, it's usually negligible compared to total drive capacity.

Platform-Specific Recommendations

Different platforms have different optimal formats.

YouTube

Best: MP4 with H.264 Why: YouTube transcodes everything anyway. MP4 uploads fast and processes smoothly. Using 4K? Still use H.264, just at higher bitrate.

I tested uploading the same video as MP4, MOV, and WebM. The final quality on YouTube was indistinguishable. The MP4 uploaded fastest and showed the least processing time.

Social Media (Instagram, TikTok, Facebook)

Best: MP4 with H.264 Why: These platforms aggressively recompress everything. Your format choice barely matters for final quality. MP4 just works.

Streaming Devices (Roku, Chromecast, Apple TV)

Best: MP4 with H.264 Why: Universal compatibility. H.265 works on newer devices but H.264 works on everything.

Personal Media Server (Plex, Jellyfin)

Best: MKV with H.265 if you want features; MP4 with H.264 if you want compatibility Why: Depends on your devices. Newer systems handle MKV with H.265 and you benefit from multiple audio tracks and subtitles. Older devices might require transcoding, which uses server resources.

Client Deliverables

Best: Ask the client, but if they say "whatever," use MP4 with H.264 Why: Eliminates compatibility questions. Clients can view on any device without installing special software.

Mistakes I've Made

Mistake 1: Choosing Format Based on Technical Superiority

My ProRes disaster. I chose the technically superior format without considering who needed to watch the videos. Technical excellence that nobody can access is worthless.

Lesson: Choose formats for your actual use case, not theoretical best quality.

Mistake 2: Assuming Newer Is Better

I encoded videos in H.265 assuming newer codec equals better choice. Many recipients couldn't play them smoothly.

Lesson: Newer technology needs time for adoption. H.264 is older but more widely supported.

Mistake 3: Not Testing on Target Devices

I created a video for a corporate presentation, encoded it beautifully, sent it off. The day of the presentation, their conference room system wouldn't play it.

Lesson: If possible, test playback on actual target devices before finalizing format choices. At minimum, ask what they successfully played before.

Mistake 4: Ignoring File Sizes for Web

I embedded a 200 MB MP4 on a website because "quality matters." The page loaded slowly on mobile connections, and many visitors left before seeing the video.

Lesson: For web use, optimize aggressively. Visitors won't notice slightly lower bitrates, but they will notice slow loading.

Mistake 5: Converting Between Formats Repeatedly

I received an AVI, converted to MOV for editing, exported to MP4 for client review, then re-exported to different MP4 settings after feedback. Each conversion degraded quality slightly.

Lesson: Minimize conversion steps. Each lossy-to-lossy conversion reduces quality. Keep high-quality masters and only convert once for final delivery.

The Tools I Use

For Conversion

When I need to convert between formats, quality matters. Poor converters create artifacts, stuttering, and sync issues.

For most conversions, I use Practical Web Tools' video converter. Everything processes in my browser, so my videos never upload to external servers. This matters for client work and personal family videos.

For Editing

I use DaVinci Resolve (free version) for most video editing. It handles multiple formats well and exports to standard formats without issues.

For Playback Testing

I keep VLC Media Player installed. It plays virtually any format, which helps me identify whether playback problems are format issues or device limitations.

What Actually Matters

After several years of working with video formats, I've realized most technical details don't matter as much as I initially thought.

Codec matters more than container. The compression method affects compatibility and quality far more than the file wrapper.

Compatibility matters more than efficiency. A video that plays everywhere is more valuable than a video that's 30% smaller but requires specific software.

Use case determines "best." There's no universal winner. The right format depends entirely on who needs to watch and on what devices.

Bitrate matters more than format. A high-bitrate H.264 video looks better than a low-bitrate H.265 video. Don't obsess over format while ignoring bitrate settings.

My Current Workflow

For family videos and personal projects:

• Master files: MOV with ProRes (for quality and editability)
• Distribution copies: MP4 with H.264 (for universal playback)
• Personal archive: Sometimes MKV with H.265 (for features and efficiency)

For client work:

• Working files: Whatever my editor handles best (usually MP4 with H.264)
• Deliverables: MP4 with H.264 unless client specifically requests otherwise

For YouTube and social media:

• Always MP4 with H.264 at appropriate bitrates for resolution

This workflow acknowledges that different stages need different formats. The editing format doesn't have to match the distribution format.

Moving Forward

That four-day re-encoding disaster taught me that video formats aren't about finding the objectively best choice. They're about matching the format to your specific situation.

My parents don't care about codec efficiency or technical superiority. They want to click a file and have it play on their TV. MP4 with H.264 does that reliably.

Professional editors need format characteristics that average viewers never think about. For those use cases, MOV with ProRes is appropriate.

The format you should choose depends entirely on answering: who needs to watch this, on what devices, and what do they care about?

For most people, most of the time, the answer is MP4 with H.264. It's the reliable, boring choice that works.

Those 200 family videos? They're all MP4 with H.264 now. Every family member can watch them on any device. That's more valuable than having slightly smaller files or marginally higher quality that requires specific software to view.

Need to convert between video formats? Try our video converter - all processing happens in your browser, nothing uploads to external servers. Your videos stay private on your device.

Frequently Asked Questions

What is the best video format for universal compatibility?

MP4 with H.264 codec is the best format for universal compatibility. It plays on virtually every device made since 2010: all smartphones, tablets, smart TVs, game consoles, streaming devices, and web browsers. When you need a video to "just work" everywhere, MP4 with H.264 is the safe choice.

What is the difference between a video container and codec?

A container (MP4, MOV, MKV, AVI) is the file format that holds the video - like a lunchbox. A codec (H.264, H.265, ProRes, VP9) is how the video is actually compressed - what's inside the lunchbox. The same codec can go in different containers. Compatibility depends on both the container AND the codec.

Should I use H.264 or H.265 for video?

Use H.264 for maximum compatibility - every device plays it. Use H.265 (HEVC) when file size matters AND you've confirmed all playback devices support it. H.265 offers 40-50% smaller files at equivalent quality, but many older devices (2018 and earlier) struggle with playback. When in doubt, use H.264.

Why won't my MOV file play on Windows or Android?

MOV files often use ProRes codec, which is designed for Apple's professional video ecosystem. Windows and Android devices typically don't support ProRes natively. The solution: convert to MP4 with H.264 codec for sharing, or keep MOV/ProRes only for editing on Apple systems.

What video format should I use for YouTube?

Use MP4 with H.264 for YouTube uploads. YouTube accepts other formats but transcodes everything internally anyway. MP4/H.264 uploads fastest and processes smoothly. For 4K content, still use H.264 but at higher bitrate - YouTube handles the transcoding to their preferred delivery formats.

What is the best format for video editing?

MOV with ProRes codec is ideal for video editing - it offers minimal quality loss through multiple edits and fast encoding/decoding. The trade-off is large file sizes (50+ GB per hour). If storage is limited, MP4 with H.264 works for editing but may show more quality degradation with repeated exports.

Why are my MKV files not playing on my TV?

Many smart TVs, especially older models, don't support MKV containers. MKV is popular for personal media libraries but lacks universal device support. Solution: convert MKV to MP4 for TV playback, or use a media server like Plex that can transcode MKV files in real-time.

What video format has the smallest file size?

For equivalent visual quality, WebM with VP9 or MP4 with H.265 (HEVC) produce the smallest files - approximately 40-50% smaller than H.264. However, compatibility is more limited. Choose file size optimization only when you've confirmed your target devices support these newer formats.

Should I convert my old AVI files?

Yes, convert AVI files to MP4 with H.264. AVI is an outdated format from 1992 with limited codec support and no modern features. Converting to MP4 improves compatibility, often reduces file size, and makes files easier to stream. Keep original AVI files as backups until you've verified conversions.