Forgot Your Excel File Password?

Supported File Formats

AccentEPR supports every version of Microsoft Excel, from Excel 6 through Excel 2024 and Microsoft 365. The level of protection depends on the version: Excel 97–2003 (.xls) uses weak RC4 encryption, while Excel 2007 and later (.xlsx, .xlsm, .xlsb) employs AES-128 or AES-256 with thousands of hashing iterations (PBKDF2 key stretching). This directly affects how fast the Password to Open can be recovered.

How to tell which version you have? Check the file extension: .xls means 97–2003, .xlsx/.xlsm/.xlsb means 2007 or later. AccentEPR detects the format and encryption method automatically when you open the file.

Instant Recovery and Removal

Sheet protection (Protect Sheet), workbook structure (Protect Workbook), edit restrictions (Password to Modify), and VBA project passwords do not encrypt the file contents. They are stored as hash values inside the document structure. AccentEPR removes them instantly, with no brute-force search, regardless of password length or complexity.

This is the key difference from the Password to Open, which encrypts the entire file and requires a full brute-force attack to recover.

Password to Open: Recovery Speed

Recovering the Password to Open means testing candidates from a defined range, and the speed depends on the file's encryption. With Excel 97–2003 and its RC4 cipher, AccentEPR runs through tens of millions of passwords per second. With Excel 2007+ and AES-128/AES-256 plus PBKDF2, that number drops to thousands per second.

Three factors determine overall recovery time: Excel version, password complexity, and processor performance. Performance-critical sections of AccentEPR are hand-optimized in assembly for specific Intel and AMD processor families.

For Excel 2007–2024 files, recovery speed can be increased using NVIDIA, AMD, or Intel GPUs. GPU acceleration is available in Accent OFFICE Password Recovery.

Narrowing the Search with a Positional Mask

If you remember part of the password, a positional mask can cut the search space by hundreds of times. You specify the allowed characters for each position, and AccentEPR only tests combinations that match.

For example, a targeted mask for an 8-character password (?0*s?d?d – letters and digits) reduces the search space from 218 trillion down to 61 billion candidates. What would take months of exhaustive brute-force fits into hours. This estimate is based on the Excel 97–2003 format.

See mask examples

Testing Real-World Passwords with Dictionary Mutations

Many passwords are built from words, names, or dates already found in common dictionaries. AccentEPR loads up to four dictionaries at once, combines them, and applies mutation rules: capitalize the first letter, append a year, swap a for @, and more, over 20 mutation types in total. This approach finds compound passwords like My$tr0ng20Zb far faster than exhaustive brute-force.

A preview window shows the mutation output before you launch the attack.

Watch a video on how mutations work

Automating Recovery with Attack Scenarios

When you are not sure which method will work, you build a scenario with any combination of attacks. Any type, any order, any number of steps. AccentEPR runs them one after another and stops as soon as the password is found. No manual switching between attacks.