GIMP Proposes New File Format to Replace 30-Year-Old XCF Standard

The GIMP Project published its latest development update on August 16, 2026, reporting on the progress being made towards GIMP 3.4 and beyond. At its core is the design and implementation of a new project file format, intended to replace the XCF format that has been in use since 1997, spanning nearly 30 years.

For GIMP, known as the open-source alternative to Adobe Photoshop, the overhaul of the project file format represents more than just an internal specification change. It is a foundational change that will enable future expansions, including more efficient file operations, auto-save functionality, support for large and multi-page projects, and improved compatibility with the animation features planned for GIMP 3.6.

According to a report by Michael Larabel of Phoronix, the new file format is based on a ZIP-compressed XML structure. This design allows for more efficient file operations compared to the traditional XCF format and ensures the flexibility needed to implement new features like auto-save. Furthermore, it is expected to offer superior compatibility with the animation features planned for future releases.

The 30-Year Legacy of the XCF Format

The XCF (eXperimental Computing Facility) format has served as the primary project file format since GIMP first adopted it in 1997. Capable of preserving editing states for layers, channels, paths, and selections, XCF grew alongside GIMP’s feature expansion and played a central role in allowing users to resume work from where they left off.

However, the XCF format’s design strongly reflects the technical constraints of the 1990s. Its binary-based structure has low readability, and extending the format involves the dual challenges of parsing a binary format and maintaining backward compatibility. Particularly when handling large projects or multi-page documents, issues such as increased file size and decreased performance during saving and loading had become problematic.

The new ZIP-compressed XML structure is a direct response to these challenges. XML is a human-readable, text-based structure that simplifies debugging and integration with external tools. ZIP compression helps reduce file size, thereby improving the save efficiency of project files that contain image data.

Technical Advantages of the New Format

The greatest advantage of the new file format lies in its efficient file operation. The XML structure allows for partial reading and writing, enabling access to specific layers or pages without loading the entire project. This has the potential to greatly improve the editing workflow for large projects.

The new format also makes it easier to implement an auto-save feature. The ability to perform partial updates to the XML structure allows for an efficient design of a mechanism to periodically save the state during editing. This reduces the risk of losing work data due to crashes or system failures, which is of great value to professional users.

Improved compatibility with the animation features planned for GIMP 3.6 is also a key advantage of the new format. Animation data requires holding frame-by-frame information, which was difficult to represent in the traditional XCF format. In the new format, frame structures can be naturally expressed within the XML structure, which is expected to lead to a smoother implementation of the animation features.

Policy on Maintaining Backward Compatibility

The GIMP Project has clarified its policy to maintain backward compatibility with the XCF format even after transitioning to the new file format. This will allow existing XCF files to be opened in newer versions of GIMP. Conversely, projects saved in the new format cannot be opened in older versions of GIMP, but this is a standard trade-off in file format migrations.

Migrating a file format is a change that requires a long-term perspective for the user community. For users with existing assets of project file, maintaining backward compatibility is a crucial element in reducing migration costs. The GIMP Project’s clear stance on this point can be appreciated as consideration for its users.

Development Trends Beyond XCF

Alongside the development of the new file format, several feature enhancements are also underway in GIMP. Brush improvements aim to increase expressiveness in digital art creation. The extension of non-destructive filter code enhances the flexibility of the editing process, strengthening a workflow that allows a随時 return to the pre-processed state.

Strengthening support for the Adobe PSD format is also an important topic. File compatibility with Photoshop is one of the primary barriers to adopting GIMP in professional environments, and improving PSD support directly enhances GIMP’s practicality. Furthermore, integration with native file chooser dialogs improves compatibility with various desktop environments.

These developments indicate that GIMP is continuing to evolve from a mere open-source image editor into a full-fledged tool suitable for professional use.

Implementation Planned for GIMP 3.4 and Beyond

The new file format is being designed with its full implementation in GIMP 3.4 as the goal. However, at this stage, it is still in the design and initial implementation phase, with no release date set. Its full utilization in GIMP 3.6, which includes animation features, is contingent upon the stability and feature expansion of the new format.

Progress on development and technical details can be confirmed on the GIMP Project’s official website. The introduction of the new file format will mark an important turning point in GIMP’s history and will form the foundation for future feature development.

Editorial Opinion

This transition to a new file format can be evaluated as having a significant long-term impact, as it will modernize GIMP’s development foundation. The move from a binary format to an XML-based one is not only an elimination of technical debt but also an investment that will accelerate the pace of future feature additions. Within the next 3 to 6 months, it is highly likely that the design of the new format will be concretized within the GIMP 3.4 development cycle, with developer documentation and preview implementations being released. Given the announced policy of maintaining backward compatibility with the existing XCF format, the migration risk for users appears limited. Looking at a 1 to 3-year span, the format refresh could become a factor in strengthening GIMP’s competitiveness. In particular, features like auto-save, multi-page support, and animation could become important decision-making factors for businesses and creators considering adoption for professional use. It might become a catalyst for users who have issues with Adobe product subscription costs to seriously consider migrating to GIMP. On the other hand, file format compatibility is the biggest barrier in software migration, and the stability of the new format and the maturity of its ecosystem will be key.

References

• “GIMP Making Progress On New Project File Format After Nearly 30 Years With XCF”, by Michael Larabel — Phoronix, 2026-08-16T20:15:33.000Z (ARR)
• Source URL: https://www.phoronix.com/news/GIMP-New-File-Format-2026