Is MPG actually the same format as MP4 for video files?

Mac
1

I found a bunch of old videos saved as MPG and I’m not sure if they’re basically the same as MP4 or if I should convert them. I want to play and edit them on modern devices without losing quality. Can someone explain the real differences between MPG and MP4, and when it makes sense to convert one to the other?

2

No, MPG and MP4 are not the same, although people often confuse them because both come from MPEG standards.

The short explanation is: MPG is an older video container usually using MPEG-1 or MPEG-2 video, while MP4 is a newer and more flexible container that can use modern codecs like H.264 and H.265.

MPG (MPEG)

MPG files were very common years ago, especially for DVDs and older digital video. You still see them sometimes in old video collections or recordings from older cameras.

From my experience they usually play easily, but the files tend to be bigger compared to modern formats. The quality is fine for older content, but not very efficient by today’s standards. It feels more like a legacy format now, still usable but not something I would choose for new videos.

MP4

MP4 is basically the modern standard for video files. Most videos you download today are MP4 because it works on almost everything and supports modern compression like H.264 or H.265.

What makes it practical is the balance between quality and size. You can get good quality without huge files, and compatibility is still very good across devices. That’s why it became the default format for sharing and streaming.

Players that handle these formats well

On Mac I usually used Elmedia Player when I had different types of files including MPG. It tends to open older formats more reliably than the default player and generally feels more flexible if you have a mixed video collection. It also handles MP4 without any issues and overall feels more like a full media center than a basic player.

On Windows SMPlayer handles both MPG and MP4 without much trouble. It feels more straightforward and reliable for everyday watching, especially if you just want something that plays everything without setup.

MPG and MP4 are not the same. MPG is more of an older format you mostly see with legacy video, while MP4 is the modern standard most people use now.

If I had to choose today, I would always pick MP4 unless I had some specific reason to keep MPG (like old recordings).

1 Like
3

Short answer for your situation: MPG and MP4 are different formats, and you should keep the MPG as your lossless-ish “source” and create MP4 copies for modern use.

Key points, focused on what you want to do:

  1. What MPG usually is

    • Container: MPEG Program Stream (often .mpg or .mpeg)
    • Typical video codec: MPEG‑2 (sometimes MPEG‑1)
    • Typical audio codec: MP2 or AC3
    • Era: DVD, old TV capture devices, old camcorders

    MPEG‑2 uses older compression. For the same visual quality, it needs a higher bitrate than H.264 in MP4. So your files are bigger than they need to be.

  2. What MP4 usually is

    • Container: ISO Base Media File Format (.mp4)
    • Typical video codec: H.264, H.265, AV1
    • Typical audio codec: AAC
    • Era: phones, YouTube downloads, streaming

    H.264 at, say, 2–3 Mbps can look similar to MPEG‑2 at 5–6 Mbps for SD content. That is why MP4 saves a lot of space.

  3. Are they “the same format”
    No.
    .mpg usually means MPEG‑2 video in an older container.
    .mp4 usually means H.264 or newer video in a newer container.
    File extension alone does not define quality. It only tells you the wrapper.

  4. Playback on modern stuff

    • Most phones, TVs, browsers handle MP4 much better than MPG.
    • Some smart TVs do not like MPEG‑2 in MPG over USB or network.
    • Windows and macOS still play MPG, but support is less consistent.

    If you want zero friction on modern devices, MP4 is safer.

  5. Editing concerns and quality
    Here I slightly disagree with @mikeappsreviewer.
    For light cutting and trimming, MP4 H.264 is fine.
    For heavier editing, older MPEG‑2 in MPG is also not ideal, but many NLEs handle it better than long GOP H.264 from phones.

    Best plan if you edit a lot:

    • Keep the original MPG as archive.
    • When you edit a specific video, transcode that MPG to an intermediate codec like ProRes or DNxHD/HR, edit that, then output MP4 for delivery.
      That avoids extra generational loss on the whole archive.

  6. Should you convert the whole stack
    Depends on your goal:

    If you care about storage and playback:

    • Yes, convert to MP4 H.264.
    • Use a high enough bitrate so you do not see a quality drop. For SD MPEG‑2 sources, 2.5–4 Mbps H.264 is often enough. Do short tests.
    • If your MPG is 720x480 or 720x576 interlaced, first deinterlace correctly, do not upscale, then encode to H.264.

    If you care max about preservation:

    • Keep all MPG files as your “masters”.
    • Create MP4 copies for viewing and sharing.
      Storage is cheap compared to re‑shooting stuff you lost to bad conversion.

  7. Tools and workflow tips

    • Use MediaInfo to check what is actually inside each MPG.
    • Use ffmpeg or a GUI like HandBrake to convert.
    • For long-term access on macOS, Elmedia Player is good, it plays both MPG and MP4 without codec packs and handles weird legacy files. That keeps you from needing to convert everything right away.

Simple action plan for you:

  1. Pick one MPG.
  2. Check resolution and interlace with MediaInfo.
  3. Convert it to MP4 H.264 using HandBrake or ffmpeg:
    • Same resolution as source.
    • Deinterlace if needed.
    • Start with about half to two thirds the original MPEG‑2 bitrate.
  4. Compare side by side on your target screen.
  5. If quality looks the same to your eyes, use those settings for batch conversion.
  6. Keep the original MPG folder on a backup drive.

That gives you modern, small, easy MP4s for daily use and preserves your old MPG videos without throwing away data.

4

Nope, MPG and MP4 are not “basically the same,” but they can look the same to your eyes if handled right.

@mikappsreviewer and @sonhadordobosque already nailed most of the technical differences (container vs codec, old MPEG‑2 vs newer H.264/H.265, etc.), so I’ll skip re‑explaining that whole thing.

Here’s a slightly different angle focused on what you actually do with those files:

  1. Don’t judge by the file extension
    .mpg just tells you “some kind of MPEG Program Stream.” It does not guarantee quality, only that it’s using that old structure.
    .mp4 tells you “modern container,” but inside it could be trash quality H.264 at 500 kbps or really nice AV1.
    So: extension is workflow info, not quality info.

  2. Converting is always lossy in your case
    This is where I partly disagree with the “just convert everything” vibe.
    MPG with MPEG‑2 is already lossy. If you convert to MP4 (H.264), you add another lossy step.
    Even if it “looks the same” to you, strictly speaking you’re not preserving every bit of what’s left.
    So if any of these videos are important (family, rare footage), keep the original MPG as the “master,” no debate.

  3. When conversion actually makes sense
    I’d convert when:

    • You’re tight on storage.
    • You want everything to just play on phones, TVs, consoles, browsers.
    • You’re mostly watching and lightly trimming, not doing heavy color grading or VFX.

    For that use, transcoding to MP4 H.264 with decent bitrate is totally fine. You’ll gain compatiblity and save space. Just don’t delete the originals if you can avoid it.

  4. Editing reality check
    Both MPEG‑2 in MPG and H.264 in MP4 kinda suck as true “editing formats.”
    If you’re doing real editing (cuts, effects, color, multiple passes), a better approach is:

    • Keep MPG as is.
    • When you want to seriously edit one video, convert that one to an intermediate codec (ProRes, DNxHD/HR, CineForm, etc.).
    • Edit in that, then export a final MP4 for delivery.

    Batch converting your whole MPG library to MP4 “for editing” is solving the wrong problem.

  5. Playback on modern stuff without going conversion-crazy
    You do not have to convert everything just to watch it on a modern machine. Software is way better than it used to be.
    On macOS specifically, something like Elmedia Player is a nice shortcut. It plays MPG, MP4, and a bunch of other weird formats without you hunting down codecs. That way you can:

    • Leave your archive as MPG.
    • Only convert the files you actually need on a phone/TV that refuses MPEG‑2.

    This avoids spending a weekend transcoding a pile of footage you may never watch again.

  6. What I’d personally do in your shoes

    • Step 1: Keep the MPG files. Treat them as “tapes” or masters.
    • Step 2: Install a player that handles both (Elmedia Player on Mac, or any decent multi‑format player on other OSes).
    • Step 3: For any clip you want to share or watch on a picky device, convert that clip to MP4 with H.264.
    • Step 4: If you discover a project you want to seriously edit, then do a proper intermediate‑codec workflow from the original MPG.

So no, MPG is not “the same” as MP4, but it’s also not some ticking time bomb you must mass‑convert right now. Treat MPG as your source, MP4 as your modern distribution format, and you’ll be fine.

5

MPG and MP4 are different, but for your goals the trick is deciding what you treat as “master” vs “daily use,” not obsessing over the extensions.

Where I partly disagree with @sonhadordobosque / @himmelsjager / @mikeappsreviewer is on how aggressive you need to be about converting everything. Converting the whole archive upfront solves compatibility but also:

  • Adds a second generation of compression to already lossy MPEG‑2
  • Eats a lot of time for material you may never touch again

A more practical split:

1. Archival vs convenience

  • Treat the original MPG as your “film negative.”
  • Use MP4 as your “distribution copy.”
  • Only transcode what you actually watch, share or edit right now.

If someday a better codec or AI upscaler appears, you will be glad you still have the untouched MPG instead of a double‑compressed MP4.

2. Editing reality

Everyone is correct that both MPEG‑2 (in MPG) and H.264 (in MP4) are long‑GOP and not ideal for heavy editing. I would avoid re‑encoding the entire library “for editing.” Instead:

  • For serious work on a specific clip, convert that one MPG to a proper intermediate (ProRes, DNxHD/HR, CineForm, etc.), edit, then export MP4.
  • For light trims and cuts, editing an MP4 derived from the MPG is fine, but keep the MPG so you can redo it later if needed.

3. Playback without mass conversion

Modern players can usually decode MPEG‑2 just fine, which means you do not have to panic‑convert everything just to watch it on a laptop.

On macOS, Elmedia Player is actually a solid way to bridge old MPG and modern MP4 in one place:

Pros of Elmedia Player

  • Plays MPG and MP4 in the same UI, plus a bunch of legacy formats
  • No codec pack hunting, good for a “dump folder” of random old files
  • Nice for checking quality differences when you A/B your original MPG against a test MP4 encode

Cons of Elmedia Player

  • It is still just a player, not a converter or editor, so you will need other tools for proper transcoding
  • Extra app to install and maintain if you were hoping to live inside system defaults only

Compared to what @sonhadordobosque and @himmelsjager suggested, I would lean even more on a capable player first, conversion second. @mikeappsreviewer’s advice to keep MPG as your lossless‑ish “source” is exactly right, I would just stress that you do not need to decide the fate of the whole archive today.

4. When to actually convert to MP4

Convert a given MPG to MP4 when:

  • A specific device refuses to play MPEG‑2 (some TVs, consoles or browsers)
  • You want to save space on clips you know you will keep and rewatch
  • You are preparing something to share or upload

Use one or two representative files as test cases: transcode them with conservative settings, compare visually, and if you are happy, batch the similar ones. Everything else can sit as MPG on a backup drive until you need it.

In short: MPG is not “just MP4 with another name,” but it also is not something you must immediately abandon. Keep MPG as the source, create MP4s as needed for viewing and editing, and lean on a flexible player like Elmedia Player so you do not have to remodel your entire library in one go.