LittleFS data are stored inside the Flash memory (not EEPROM) and has 1MB size. To format: #include void setup() { Serial.begin(115200); if (!LittleFS.begin()) { Serial.println("LittleFS Mount Failed"); return; } Serial.println("Formatting LittleFS..."); if (LittleFS.format()) { Serial.println("LittleFS formatted successfully"); } else { Serial.println("Failed to format LittleFS"); } } void loop() { // Your code here } Show basic info: #include #include #include "SSD1306Wire.h" SSD1306Wire display(0x3c, D5, D6); // reversed! void setup() { Serial.begin(115200); Serial.println(); Serial.println(); Serial.println(); uint32_t chipId = ESP.getChipId(); Serial.print("Chip ID: "); Serial.println(chipId); uint32_t flashSize = ESP.getFlashChipSize(); Serial.print("Flash Chip Size: "); Serial.print(flashSize / 1024 / 1024); Serial.println(" MB"); Serial.println(); LittleFS.begin(); FSInfo fs_info; LittleFS.info(fs_info); Serial.printf("Total size: %u bytes\n", fs_info.totalBytes); Serial.printf("Used size: %u bytes\n", fs_info.usedBytes); Serial.printf("Block size: %u bytes\n", fs_info.blockSize); Serial.printf("Page size: %u bytes\n", fs_info.pageSize); Serial.printf("Max open files: %u\n", fs_info.maxOpenFiles); Serial.printf("Max path length: %u\n", fs_info.maxPathLength); } void loop() { // Your code here } Show files and folders: #include void listDir(fs::FS &fs, const char * dirname, uint8_t levels) { Serial.printf("Listing directory: %s\n", dirname); Dir dir = fs.openDir(dirname); while (dir.next()) { if (dir.isDirectory()) { Serial.print(" DIR : "); Serial.println(dir.fileName()); if (levels) { listDir(fs, dir.fileName().c_str(), levels - 1); } } else { Serial.print(" FILE: "); Serial.print(dir.fileName()); Serial.print(" SIZE: "); Serial.println(dir.fileSize()); } } } void setup() { Serial.begin(115200); if (!LittleFS.begin()) { Serial.println("LittleFS Mount Failed"); return; } listDir(LittleFS, "/", 0); } void loop() { // Your code here }