Synology DSM 7.4 Supported Models: 2026 Compatibility Checker

DSM 7.4.1 is the current 7.4 maintenance release

Synology released DSM 7.4.1-90080 on July 23, 2026. The release is staged, and some systems may require a manual patch from Download Center rather than receiving an automatic notification.

The checker therefore separates “supported by the release family” from “will appear automatically on this NAS today.”

DSM 7.4.1-90080 is the current 7.4 maintenance release used by this Sprint, dated July 23, 2026. A model checker should therefore answer more than “can it run DSM 7?” The exact branch, current build and model-specific release notes matter because package behavior, manual-update requirements and future upgrade ceilings can differ between generations.

The 20-series models in this Sprint remain on the 7.4 path

DS220+, DS720+, DS920+ and DS1520+ are included in the 20-series supported family, while DS1821+ belongs to the 21-series. Current Download Center and release-note pages expose DSM 7.4 for these systems.

That does not mean every package behaves exactly as it did on DSM 7.2 or 7.3, so package review remains part of a safe upgrade.

DS224+, DS423+ and DS923+ are also current 7.4 targets

Synology provides DSM 7.4 release information for the newer Plus models covered in this Sprint. These systems are not in the group announced as reaching their last upgradable DSM version at 7.4.

Owners can therefore separate “supports 7.4 now” from “7.4 is the final major upgrade.”

Some older Plus models reach their last major DSM at 7.4

Synology explicitly lists models such as DS918+, DS218+, DS1019+, DS1819+, DS2419+, DS2419+II and several 2016–2018 Plus systems as having DSM 7.4 as the last upgradable version.

For those systems, upgrading can still be sensible, but it should be paired with a longer-term replacement and security plan.

Synology also identifies a group of older systems for which DSM 7.4 is the last upgradable version. That label does not mean DSM 7.4 stops working on installation day. It means future major-version planning should assume the operating-system ceiling is approaching. Owners can use that period to validate backups, document services and decide whether the NAS will eventually move into a secondary role.

Manual-download-only does not mean unsupported

The 7.4 release notes identify older models that will not receive the update through normal device notification and instead require a patch from Download Center.

This is an operational distribution difference. Follow Synology’s instructions for the exact model and do not use a patch intended for a different DiskStation.

DSM 7.4 cannot be normally downgraded after installation

Synology’s release notes warn that after installing DSM 7.4 you cannot downgrade to a previous DSM version through the supported process.

That makes pre-upgrade package compatibility, backup verification and maintenance timing more important than on a reversible application update.

Package compatibility is part of model compatibility

A NAS can be eligible for DSM 7.4 while a package requires update, migration or removal. The release notes call out package compatibility actions, and Synology has separately ended support for older PHP and mail components.

Inventory business-critical or self-hosted packages before treating a green model result as permission to click Update immediately.

Some older models may receive a different maintenance experience, including manual patch requirements described in Synology release notes. That is why Cloudzat does not reduce compatibility to a single green badge. A technically compatible NAS can still require more administrator attention than a newer unit receiving the normal update flow.

Media behavior changed before and during the 7.4 era

Synology has moved more media codec processing toward client devices and removed Video Station from newer DSM generations. Third-party media servers have their own behavior.

Owners of older Intel DiskStations should test their actual media workflow rather than assuming DSM eligibility preserves every legacy media feature.

Backups should be verified before the major update

Hyper Backup, configuration exports and application-specific backups provide different recovery scopes. A safe upgrade has a tested copy of irreplaceable data outside the NAS.

Because normal downgrade is not available, recovery planning should focus on data and service restoration rather than assuming you can simply roll DSM back.

Use the exact model number in Download Center

Synology model names can be deceptively similar. DS423 and DS423+ are different products, as are DS925+ and DS925neo+.

The checker normalizes common Plus spellings but still requires an exact product identity before returning a supported result.

Before upgrading a production NAS, inventory packages, containers, directory integrations, backup jobs and any third-party modifications. The inability to perform a normal downgrade after installing DSM 7.4 raises the cost of discovering an incompatibility late. A verified data backup is necessary, but configuration notes and a service-recovery plan are equally valuable when the NAS hosts more than file shares.

A last-major-version notice changes replacement timing

If DSM 7.4 is the final major upgrade for your model, the NAS does not stop working when you install it. The significance is that the future feature and security path becomes more constrained after the 7.4 lifecycle ends.

Use that runway to plan replacement without rushing data migration during a hardware failure.

Treat compatibility as a living dataset

Synology can revise staged rollout notes, packages and applied-model guidance. The local checker is a reviewed snapshot and always links to current official release information.

Recheck before performing the upgrade, particularly if months have passed since the page was published.

A compatibility snapshot also needs an update date. This checker is tied to the August 2026 research state and should not be treated as permanent firmware policy. When Synology publishes a new DSM maintenance build or changes a model lifecycle, refresh the dataset before making a fleet decision. For models not explicitly recognized, the tool deliberately returns Verify Live so the uncertainty remains visible instead of being converted into a false yes or no.

For any model outside the maintained list, open Download Center and the model-specific DSM release note before proceeding. An unknown result is a research prompt, not a negative compatibility verdict.

That verification step prevents model-name assumptions from becoming upgrade mistakes.