Which File Formats Will Still Open in 2045 — and Which Ones Are Already Dead

There's a file format graveyard out there, and it's bigger than you'd think. WordPerfect documents. RealMedia streams. Flash animations. Lotus 1-2-3 spreadsheets. Kodak Photo CD images. All of these were, at some point, completely normal ways to save your stuff. Now they're either unreadable without heroic effort or gone entirely.

Here's the uncomfortable truth: the formats you're using right now — the ones that feel totally standard and permanent — are not immune to the same fate. The question isn't whether format obsolescence is real. It's whether your archive is prepared for it.

We dug into this with some people who think about it professionally, and the picture is more nuanced than "open formats good, proprietary formats bad." Survival in the format world is about adoption, documentation, and institutional will — and those things can shift.

The Formats That Digital Archivists Actually Trust

When you talk to people who work in digital preservation — librarians, archivists at universities and cultural institutions, the kind of folks whose literal job is making sure files remain readable across decades — certain formats come up again and again as genuinely safe bets.

Plain text (.txt) is essentially immortal. It's so simple that any future system capable of displaying characters at all will be able to read it. If you have anything that doesn't need formatting, plain text is the most future-proof container you've got.

PDF/A — the archival variant of PDF — is specifically designed for long-term preservation. Unlike regular PDFs, PDF/A embeds all fonts and prohibits features like encryption and external content references that could make a file unreadable in the future. The Library of Congress uses it. If something is worth keeping in document form, PDF/A is worth knowing about.

PNG for images is in a strong position. It's an open standard, widely adopted, and the specification is well-documented. TIFF is also trusted by archivists for high-quality image storage, particularly in institutional settings. JPEG is so ubiquitous it's probably not going anywhere either, though its lossy compression means every save degrades the image — something worth knowing for anything you care about preserving at full quality.

FLAC for audio sits in a comfortable spot. It's lossless, open-source, and has enough community and industry adoption that it's unlikely to become unreadable anytime soon. MP3, despite being technically proprietary in its origins, has become so deeply embedded in software and hardware infrastructure that it's probably safer than it has any right to be.

SVG for vector graphics is XML-based and open, which archivists tend to like. You can literally open an SVG file in a text editor and read the underlying structure. That kind of transparency is a good sign for long-term readability.

The Formats You Should Be Worried About

Now for the less comfortable part.

DOCX — yes, the default Microsoft Word format — is more fragile than its dominance suggests. It's technically an open standard (Office Open XML), but its complexity is staggering. The specification runs to thousands of pages, and different applications implement it differently. Rendering a DOCX file "correctly" in 20 years will depend on whether anyone has maintained the software infrastructure to do so. Archivists generally recommend converting important documents to PDF/A for long-term storage and keeping DOCX as the working copy, not the preservation copy.

HEIC, Apple's default photo format on iPhones since 2017, is efficient and modern but carries real risk. It's not as widely supported as JPEG or PNG, and its fate is tied more closely to corporate decisions than open standards bodies. If you're shooting in HEIC and not converting, you're making a bet on Apple's continued relevance and goodwill.

EPUB for ebooks is an interesting case. It's an open format, but ebook readers have fragmented its implementation badly enough that EPUBs that display perfectly on one device look broken on another. The format itself may survive, but the reading experience you intended may not.

Proprietary creative formats — PSD, AI, INDD, even older versions of Final Cut Pro projects — are among the highest-risk things in most people's archives. These are controlled by companies, and companies change their products, discontinue them, or get acquired. Adobe has been relatively good about backward compatibility, but "relatively good" is not the same as "guaranteed forever."

Video is the wild card. Container formats like MP4 are broadly safe. But the codec inside the container — H.264, H.265, AV1 — determines whether the video is actually decodable. H.264 is so dominant right now that it's probably fine for the foreseeable future. Anything more niche is a gamble.

What's Already Gone

To understand where things are headed, it helps to look at what's already been lost.

Flash (.swf) is the most culturally painful example. An entire era of internet creativity — games, animations, interactive art — is effectively gone from the live web. The Internet Archive's Flashpoint project has preserved a remarkable amount, but casual users have lost access to files they made and loved. The lesson: format survival depends on community effort, not just technical merit.

HD DVD lost a format war and took content with it. Betamax tapes. LaserDisc. 8-track. Physical media formats follow the same rules as digital ones — adoption and infrastructure matter more than quality.

The Kodak Photo CD format is a particularly sharp example. Millions of American families had their 35mm film scanned to Photo CDs in the 1990s. Opening those files today requires specific software that barely anyone maintains. The images aren't gone — technically — but accessing them is a project.

A Practical Survival Guide for Your Personal Archive

You don't need to be an institutional archivist to protect your files. A few habits go a long way:

Prefer open formats for anything you want to keep. When you're done working in a proprietary format, export a preservation copy in something open. Finished a document? Export to PDF/A. Done editing a photo? Export to TIFF or PNG alongside your PSD.

Avoid format lock-in for irreplaceable content. Your family photos shouldn't live exclusively in HEIC or in a cloud service's proprietary library format. Export them to JPEG or PNG and keep local copies.

Watch the adoption curve. Formats with massive, diverse adoption — used by governments, libraries, and multiple competing software applications — are safer than formats controlled by a single vendor. When a format becomes a standard, it tends to stay readable because too many people need it to die.

Revisit your archive every few years. Open some old files. If anything has become harder to access, migrate it forward before it becomes impossible. Think of it as maintenance, not a one-time project.

Store metadata alongside your files. A photo is more valuable if you know when it was taken and where. A document means more with context. Plain text sidecar files or well-named folder structures can carry this information even if the original file's embedded metadata is lost.

The formats that survive won't necessarily be the best ones. They'll be the ones with the most documentation, the most open access to their specifications, and the most people who cared enough to keep them alive. The good news is that caring — and acting on it — is something you can do right now, before the next format graveyard opens up.