I'm confused about my esp8266-01 if they have SPIFFS or not. Is there a way to find it out? If they have, how to get their size?

I've got the following flash id: 0x1440e0.

Example SPIFFS apps keep crashing with wdt reset and lots of dumped hexes.

  • SPIFFS size is determined by you when you upload the sketch Mar 25, 2018 at 7:20

1 Answer 1


First you need to know the size of the flash memory attached to esp8266 on your module. Common sizes are 512 kB (4Mbit), 1 MB (8Mbit) and 4 MB. Espressif Flash Download Tool (Windows) or esptool can determine it.

You can choose the size of the SPIFFS in your flash 'layout' by selecting the option in IDE Tools menu. Take one according to for you flash size and size of the files you want to put into SPIFFS.

If you have 1 MB flash on your module and you want to use OTA upload, let flash space for twice a space taken by the sketch.

  • All the data like WiFi config and binaries go to the flash memory? There is no other dedicated memory for those?
    – haxpanel
    Mar 25, 2018 at 11:56
  • 1
    no. esp8266 uses the flash memory like a PC uses a hard-drive
    – Juraj
    Mar 25, 2018 at 12:01
  • Also, more importantly, I'm getting wdt reset errors with sometimes lots of hex dumps after uploading SPIFFS example apps. I've set the SPIFFS size to 512 (of 1M flash), but not sure if the Flash mode is correct. Any idea? Thanks
    – haxpanel
    Mar 25, 2018 at 12:01
  • did you upload the SPIFFS image with the SPIFFS upload IDE plugin?
    – Juraj
    Mar 25, 2018 at 12:03
  • I've tried that as well as formatting the SPIFFS using the example code. Not sure what would be a working strategy. I've tried the following among others pastiebin.com/5ab790f66e9a1
    – haxpanel
    Mar 25, 2018 at 12:04

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