Securely erasing free space on an SSD: Does overwriting harm the SSD, and what does Protectstar recommend?

The short answer is: Yes, free space on an SSD can be securely erased—but with moderation. In the current FAQ, Protectstar explains that securely overwriting free space on SSDs with iShredder is generally possible without significantly affecting the SSD’s lifespan, as long as a reasonable number of overwrite cycles is used. Protectstar recommends 1 to a maximum of 8 passes and advises using the feature occasionally, not unnecessarily often.

Why is this topic controversial at all? Because SSDs work differently from classic hard drives. Flash storage has a limited write endurance, and the controller distributes writes across many cells through wear leveling so the same areas are not stressed over and over again. That is exactly why people have debated for years whether classic overwriting makes as much sense on SSDs as it does on HDDs. Protectstar itself addresses this concern in the FAQ and argues that modern SSDs are robust enough in everyday use—as long as you do not overdo it.

At the same time, the security side matters: On the iShredder product page, Protectstar explains that manually deleted files in free space can under certain circumstances remain recoverable until that area has been securely overwritten. That is exactly what the “securely erase free space” feature is for: to overwrite remnants of data in unused areas so that later reconstruction becomes much harder or practically impossible.

For a proper classification, it is worth looking at NIST. In its current media sanitization guidelines, NIST explains that suitable purge methods vary depending on the storage medium and that, for newer storage types, media-dependent techniques such as overwrite, block erase, or cryptographic erase via special sanitization commands may also be relevant. NIST also emphasizes that—especially for flash storage and mobile devices—you should follow manufacturer-specific methods if such methods exist. For Android devices, NIST explicitly mentions eMMC Secure Erase, Secure Trim, or equivalent methods for stronger sanitization, rather than relying only on removing file pointers.

If you have occasionally deleted sensitive data or want to pass on a device, securely erasing free space with iShredder makes sense. But if you do it every day, with many passes and without a real reason, you increase write wear unnecessarily. In practical terms, that means: less, but targeted is usually better than constant extreme shredding. This also matches Protectstar’s own recommendation to overwrite more on a weekly or monthly basis rather than constantly.

For especially demanding scenarios—for example in companies, with highly sensitive data, or before final disposal—a general “free space cleanup” may not be enough as the only method. In that case, you should also check whether the drive or device supports Secure Erase, Sanitize, Cryptographic Erase, or comparable manufacturer-specific functions. NIST makes it clear that media-dependent procedures are decisive here and that Cryptographic Erase, under the right conditions, can enable very fast and effective sanitization.

The clear user version for the FAQ is therefore: Yes, securely erasing free space on SSDs is useful—but not excessively. For everyday use, a few passes and occasional use are usually enough. For maximum security, you should also consider the storage medium itself, the manufacturer’s functions, and the specific protection requirement.