TechMarch 27, 2026· 8 min read

Open Source vs Proprietary File Formats in 2026: What Actually Matters

The real-world differences between open and closed file formats. Why some formats lock you in, and which ones give you freedom.

Here's the thing: most people don't think about file formats until they can't open something. You download a file, double-click it, and... nothing. Or it opens in the wrong app. Or worse, you're told you need to buy software just to see your own work.

That's the proprietary format trap. And in 2026, it's still everywhere.

What We're Actually Talking About

An open source file format is one where the specification is publicly available. Anyone can read the technical details and write software to create or open files in that format. Think PNG for images, MP3 for audio (after the patents expired in 2017), or WebM for video.

A proprietary format is controlled by a single company. The specifications might be partially public, fully secret, or wrapped in patents and licensing agreements. Examples: PSD (Adobe Photoshop), PAGES (Apple Pages), DWG (Autodesk AutoCAD).

The difference matters more than you think.

The Lock-In Problem

Let's say you've been designing in Sketch for five years. You have 200+ files. One day Sketch changes their business model or goes under (it happens). Your files are in .sketch format, which only Sketch can fully read.

Sure, you can export to SVG or PDF. But:

  • That's 200 files to manually export
  • You lose layers, symbols, and metadata
  • Any future edits need the original format
  • If Sketch is gone, you're stuck

This is vendor lock-in. Your data is held hostage by the format.

Open formats don't have this problem. If you save everything as PNG and SVG, literally dozens of apps can open them. The format outlives any single piece of software.

Real-World Examples That Matter

Images: JPEG, PNG, and GIF are open. HEIC (Apple's photo format) is technically "open" but wrapped in patents — which is why Windows and Android took years to support it properly. Apple pushed HEIC because it saves space, but the friction it caused proves the point: if one company controls adoption, everyone else suffers.

Documents: PDF is technically proprietary (Adobe owns it), but the specification is ISO-standardized and freely available. That's why every OS can open PDFs. Compare that to .pages or .docx files with advanced features — good luck opening those without the right software. Need to work with PDFs? Tools like KokoConvert let you merge, split, and convert them without installing anything.

Video: MP4 (H.264) is the standard, but it's patent-encumbered. Google created WebM and VP9 as truly open alternatives. In 2026, AV1 is finally getting traction as the next-gen open codec. But H.265 (HEVC) is still locked behind licensing fees, which is why browser support is patchy.

Audio: MP3 was proprietary until 2017. Now it's free. OGG Vorbis and Opus were created as open alternatives. FLAC is fully open and loved by audiophiles. Meanwhile, Apple's ALAC is "open" but barely supported outside the Apple ecosystem.

When Proprietary Formats Make Sense

Look, I'm not going to pretend open formats are always better. Sometimes proprietary formats exist because they genuinely innovate.

PSD files are massive and inefficient, but they preserve every layer, blend mode, and adjustment in Photoshop. No open format does that as well (yet). If you're a professional designer, you need PSD.

The key is: use proprietary formats as working files, but always have an open export.

Save your Photoshop project as PSD. But also export a PNG or TIFF. Work in Final Cut? Fine. But render to MP4. Keep your .pages file if you want, but save a PDF backup.

The Patent Trap

Some formats look open but are full of patents. HEIC, HEVC (H.265), and AAC all have public specs, but implementing them legally requires paying licensing fees.

This is why:

  • HEIC support is inconsistent across platforms
  • Free software often can't include HEVC encoding
  • Browser support for these formats is a mess

Compare that to VP9, AV1, or Opus — fully open, no licensing required. Anyone can implement them. That's why they spread faster and work everywhere.

What You Should Actually Do

For most people, the strategy is simple:

1. Default to open formats when you can

Saving a photo? PNG or JPEG. Audio file? MP3 or FLAC. Document? PDF is your friend. Video? MP4 with H.264 is still the safest bet (even though it's patent-encumbered, it's universal).

2. If you must use proprietary formats, keep backups in open ones

Working in Photoshop? Export PNGs. Editing in Pages? Save a PDF. Recording in Logic Pro? Bounce to WAV. You get the idea.

3. Check compatibility before committing

Before you save 500 files in a format, make sure you can open it on all your devices. If you're on iPhone and your work laptop is Windows, HEIC photos will be a pain. Convert them to JPG and save yourself the trouble.

4. Use conversion tools when you're stuck

Already have a bunch of files in a proprietary format? Convert them while you still can. Don't wait until the software is discontinued.

The Future: Slow Progress

Open formats are winning, but slowly. AV1 video is finally getting hardware support in 2026. AVIF images are becoming mainstream (though still with patent concerns). JPEG XL failed to gain traction because browser vendors didn't prioritize it.

The big tech companies still love their proprietary formats. Apple isn't going to stop pushing HEIC. Adobe isn't opening up PSD. Autodesk still charges for DWG.

But the trend is clear: open formats become dominant eventually. They just take longer to get there because no single company is pushing them.

Why This Matters for You

If you're just saving photos from your phone, this might feel abstract. But think about this: in 10 years, will you still be able to open your files?

I have documents from the '90s saved in WordPerfect format. I can't open them anymore. The software is gone. The format is abandoned. My work is effectively lost.

Meanwhile, I have plain text files from 1995 that open perfectly in any editor. That's the power of simple, open formats.

So yeah, file formats matter. More than most people realize. And the choice between open and proprietary isn't just technical — it's about who controls your data.

Choose wisely.

Frequently Asked Questions

What makes a file format "open source"?
An open source format has publicly available specifications that anyone can implement without licensing fees. Examples include PNG, MP3 (after patents expired), and WebM. Anyone can write software to read or create these files.
Are proprietary formats always bad?
Not necessarily. Some proprietary formats like HEIC offer better compression than open alternatives. The issue is vendor lock-in — if only one company controls the format, you depend on them for access to your own files.
Can I convert proprietary formats to open ones?
Yes, in most cases. Tools like KokoConvert can convert between formats. For example, you can convert HEIC to JPG or Pages to PDF. The key is doing it before you have thousands of files locked in a format you can't easily open.
Why do companies create proprietary formats?
Several reasons: controlling the ecosystem, collecting licensing fees, adding features their software needs, or making it harder for users to switch to competitors. Sometimes it's technical innovation, sometimes it's business strategy.