Restore ECU files to their correct flash size

🚀 Getting Started

Access our free online tool:

Open Filesize Converter

No installation required — upload and convert directly from your browser.

🔍 What does this tool do?

Some ECU reading tools (like Autotuner) save files smaller than the real ECU flash size. This causes issues when writing back because the file does not match the expected layout.

This tool restores the correct size by adding missing 0xFF padding before your original data.

Input: ~2MB (incorrect size)
Output: 8MB (correct size)

⚙️ How it works

• Select the ECU type (defines size and offset)
• Upload your original file (Autotuner or similar)
• Click Convert & Download

The tool fills missing space with 0xFF and appends your data correctly.

🧰 Compatibility

• Autotuner
• Any tool producing undersized reads

⚠️ Important:
Always verify the converted file with a checksum tool before writing it back to the ECU