Stellar Knowledge Base

How to repair JPEG image file when it throws Unknown JPEG Format error while trying to open it?

December 4, 2018     139509 views     1     1

Sometimes you encounter Unknown JPEG format error when you try to open a JPEG image file. For common people, this error is just a loss of some memories, but for a professional photographer or graphic designers, this error may come with the loss of their business as they lose the accessibility of some of their very crucial photos. However, the main reason of encountering this error message is damage or corruption of JPEG image file.

Let us discuss the major causes behind the corruption of a JPEG image file:

Main causes of JPEG image file corruption:

  • Generation of bad sectors in the hard disk sometimes corrupts the stored JPEG files, and you encounter the above-mentioned error message when you try to open a JPEG image file
  • Virus infected storage media also corrupts JPEG image files, and you become unable to access them
  • Corrupt or broken header of JPEG image file
  • Due to incomplete JPEG scan, we also end up corrupting our valuable pictures
  • Using the digital camera even after it indicates low battery also corrupts the clicked JPEG images and thus, you encounter the above error message when you try to view these images

However, >Stellar Repair for Photo software available to repair your corrupt jpeg file(s) which not only repair your corrupt JPEG files but also extract and repair their thumbnails if you want.

Add corrupt JPEG File with "Add File" option which you wants to fix.

  1. Select the corrupted JPEG File(s).
  2. Repair the selected JPEG/JPG image files by using "Repair" option.

As soon as you choose this option a screen which helps to see the preview of the files before saving appears. Click "Save" button to save the repaired files to the desired location.

That's it; now you can see your jpeg picture with its original form and quality.

For More Detail About the Software Visit Here:


63 User Comments

October 10, 2011 04:33 pm

Got a few files on an SD card. It has now been running for over an hour. No screen appeared which helps to see the preview files before saving appears. Just the progress bar (green) and no indication of what is happening.

Amit Pandey
November 21, 2011 05:50 am

Hey Jhon,

Progress bar itself indicates that the software is scanning your SD card or hard drive, once scanning will complete, it will automatically shows your corrupted or deleted photos for preview, if you want to see the preview in the middle of the process, you can stop the scan process in between. Also if your SD card have lots of images in it, software takes more time to scan.

BTW which software you have been used to recover your photos, because in JPEG Repair Software their is no scanning process occurs, might be you have commented on different section of the knowledge base.

Please let me know if you have any other issues.


January 16, 2012 02:45 am

Have added 10 files to jpeg repair for testing. It looks like working, friendly interface, easy to use. But the files did not recover, show msg (important marker missing), have copy to linux, run on linux and cabum bum is fixed... Anyway thanks for an effort to create that software...

Amit Pandey
January 23, 2012 04:28 am

Hi Al..

If you send me one of the non repaired JPEG file, then only I can let you know the reason why our software not able to repair your files.

Thanks & Regards,
Amit Pandey

February 29, 2012 05:34 am

Purchased Stellar Photo Recovery to try and recover photos on a SD memory card. I do not know what has happened to the SD card. I first put the SD card into my iMac and most of the pictures were visible but when I went to download them they were bright colors and the images could hardly be seen. I then tried using my camera as the card reader and hooked it put to my PC. Same issue. Some pictures were visible but when you clicked on them they became different bright colors and some with lines.

As stated above I purchased the Photo Recovery - it ran the scan and I could see my pictures. I was so excited and thought the recovery program worked. However when they were saved to the computer I had the same results as above. Hardly any of the picture images were viewable - only lines and bright colors where pictures once were.

Would appreciate any guidance you can give me.
Thank You

March 9, 2012 08:57 am

I downloaded the free Steller Phoenix Photo Recovery and have been trying to get it to work most of the night.

It starts and I can see 3 different jpgs that it found on the 3.5 floppy that I'm trying to get them from but between the 3rd and 4th jpg the program stops. I get the "Program Stopped Responding" error. Don't know how to fix this and can't seem to find a place, other than here, to post my problem.

I don't think this is the right area and I don't think I'll get an answer but I thought I had nothing to lose by trying.


March 24, 2012 06:05 pm

Hi there, I purchased the jpeg repair product to deal with a number of pictures that apparently had file errors and ended up getting the same message as Al above (Jan 16, "Important marker missing. File can't repair"). Can you advise on next steps?

Amit Pandey
April 5, 2012 02:59 am

DONNA, The thumbnail information is correct but the area where data stored is corrupted. In scan results we show preview of files using thumbnail information. Stellar Photo Recovery recovers files irrespective they are corrupted or not. Suggest you to try Stellar Repair for Photo to repair files (only if Camera is saving files in JPEG format).

cassiereroni, We are always here to help you.
In your case, Create an image of the floppy and try recovery using image. There might be bad sectors in Floppy. In Image, there will be no bad sectors.

Thanks & Regards,
Amit Pandey

Amit Pandey
April 5, 2012 03:10 am

Hi Jeff,

In your case, markers which are required to start the repairing process are missing. Repairing is not possible in this case. :(

Thanks & Regards,
Amit Pandey

April 6, 2012 12:06 pm

Hi Amit, if that's the case, can I get a refund on the product? Please also let me know by email and I will supply the invoice, etc.

Amit Pandey
April 11, 2012 03:06 am

Hi Jeff,

You can contact to our Customer Support Team any time Monday to Friday via following channels:

Email :
Phone: +1-877-778-6087 (TOLL FREE)
Chat on Skype:

Hope it will help you...

Thanks & Regards,
Amit Pandey

April 17, 2012 05:04 am

Hi Amit,

I am not able to save my recovered photos in laptop as its not showing any option to save, please can u help me in that.

Thanks & Regards

Amit Pandey
May 8, 2012 11:08 am

Hi Reena,

R u Using Licensed version of the software?

May 21, 2012 09:24 pm

as i tried to repair a jpg file I got this message

" Maple0003.jpg Important marker missing. File can't repair "

What is the problem here and why does it miss a marker, ( what does that mean) ? please help.

Amit Pandey
May 23, 2012 08:26 am

Hi Daniel,

Markers which are required to start the repairing process are missing. Repairing is not possible in this case. :(

Amit Pandey

July 7, 2012 12:32 pm

I tried six files, all which showed cray but their thumbnails were fine. It ran through it's process and files are still gray. It says it repaired them, but no error message. Does this make sense? Thanks - Jim

Amit Pandey
July 12, 2012 08:37 am

Hi Jim,

Could you please send the sample corrupt files to us, so we can see what exactly the problem with the files.
You can send us mail on amit.pandey[@]

Please remove the brackets([ ]) before sending.

Amit Pandey

King Mak
July 25, 2012 04:13 am

Hi Amit Pandey,

My JPEG header are corrupted that JPEG photos are opened in Windows.
Does the software promise to recover them?

Thanks a lot.
King Mak

Amit Pandey
July 30, 2012 03:38 am

Hi King Mak,

I advice you to first check your files with demo version of the software, if your JPEG files shown in the preview, you can 100% recover back your photos Guaranteed with the software.

Amit Pandey

August 22, 2012 01:11 pm

Is there a file size restriction with the free version of the Data Recovery Software?
Are there file size restrictions with any of the purchased versions?


September 9, 2012 04:48 am

Good afternoon,
If a JPEG file cannot be repaired due the error "important marker missing" is that an impossible recovery?
I ask as I noticed in your comment to Al on Jan 23 you mentioned having him send you a copy of the photo which would not recover.
Please advise.


September 18, 2012 04:55 am

Hi! I have the same problem when trying to repair an image, a message Important marker missing. File can't repair, does it mean that the picture can not be repaired?

Amit Pandey
September 20, 2012 05:35 am

Hi Brad,

There is no file size restriction in demo or purchased version of the software.


Amit Pandey
September 20, 2012 06:31 am

Hi Jim, Ana;

Whenever you see software shows important marker missing message it mean your file can't be repair with the software. It is basically due to wrong header type information.

A "Invalid .jpg marker" means that the internal header of the file is showing as .jpeg, but the file extension showing something else... or, vice versa. And if you see your file extension with JPEG, then somehow internal header of the file got changed or damaged.

The basic solution of this problem is to change the file extension with .jpg or change the file header. Changing the file extension is quite ease just rename the file with .jpg extension but changing header information needs some editing tool like hex editor or something else. But it required enough experience to understand the header information and to operate a hex editor.

In some cases software repair thumbnails of the actual files because it might be saved at different location.In that case it is quit possible to see the thumbnails when the file is totally damaged.


September 26, 2012 04:43 am

what is exactly jpeg repair do.. i have some jpeg files which do not open..plz help should buy the product

Amit Pandey
October 9, 2012 06:02 am

HI Steven,

I advice you to try the demo version of the software first to make sure that software can repair your files or not. If you are able to see the preview of your pictures in demo version then surely you need buy the software, it will definitely repair your files.


October 30, 2012 01:23 pm


I am getting the error message with the "important marker missing". Do you foresee future versions being able to solve this header problem.


Amit Pandey
October 31, 2012 02:31 am

Yes Mike, We are working on it and next version will surely solve this header problem.


October 31, 2012 09:32 pm


Cool! Thanks. I look forward to being a loyal customer of your company. Its saved around half my pictures. I am having problems with the other half with that "important marker missing" problem. I look forward to the new version.

What is the timeframe for the release of new version?


November 13, 2012 02:28 am

Trying to repair ALOT of images (over 5000)

Went through the repair process, but the images that didnt error out ( "important marker missing") weren't fully repaired.

There is still a lot of the picture missing in the majority of the files. Anything I can do?

December 22, 2012 01:58 am

I bought the program to get back my photos, I entered the user name and the key and it didn't work... what can I do?
Hope to hear from you soon! Thanks!

Amit Pandey
January 16, 2013 08:30 am

Hi Milagros,

Please contact the customer support team:

Email :
Phone: +1-877-778-6087 (TOLL FREE)
Chat on Skype:

They will surely help you...


Naqash ahmad
February 20, 2017 11:02 am

Hex editor Shows only FF FF FF FF and nothing in my picture view....
what is it means?

Amit Pandey
February 21, 2017 08:20 am

Hi Naqash,

The header of the photo starts with FF. In your case, the header may be corrupt. Our software repairs the corrupt header of JPEG/JPG files. Download Stellar Repair for Photo software and repair your photograph.

John C
May 29, 2013 02:31 am

I downloaded the JPEG Repair trial software and, on testing with some corrupted JPGs, it showed images with the Stellar Software text that could not be saved to examine them. I purchased your S-P JPEG Repair activation key and ran the test again. The resulting images were not processed because of a problem with the source file. The thumbnails were processed properly, although these were not previously damaged!

Can I send you a sample for your appraisal and examination. All 7,000 of my [photos were affected by a virus and I really need to recover/repair most of them!

Thanks in advance

John C

Amit Pandey
May 30, 2013 05:50 am

Hi John,

Ya Sure.... please send me some.


April 22, 2014 12:18 pm


I've tried your trial version to my curropted images and it says invalid files. Is it possible for me to send you one of the file so you can check whether it's recoverable?

If it can be recovered I will be delighted to buy this program.


Adi H

Amit Pandey
April 23, 2014 04:41 am

Hi AdiH,

We've already mentioned that this software couldn't repair or recover files with such error messages.


August 6, 2014 03:19 pm

have a problem buying your software "stellar phoenix jpeg repair", I don't have enough cash to buy, can I please have the honour to get to use your software to repair some of my corrupted photos that must be given to some orphanage when they had their anniversary.
can I get the activation key for it. It will be a pleasure, thanks

Amit Pandey
August 8, 2014 06:06 am

Hi Dan,

Thanks for Writing!!

We can’t provide you the activation key of Stellar JPEG repair software but we can help you.

Can you please provide the corrupted photos so that we can try to repair ourself. After repairing the photos, we will mailed you repaired photos.

You can mail your photos at following e-mail address:

August 8, 2014 02:47 pm

When trying to open a jpg file I simply get Invalid Image. I downloaded your trial software and tried it on one file. It gave me "1 Invalid File(s) Found. Failed to repair." Do you have a suggestion what I should do?
Is there anything in the paid version that will do a better job?
Can I send you a couple of files to look at?
Best regards,

Amit Pandey
August 11, 2014 03:18 am

Hi Ólafur

Sorry to say that if you get 1 "Invalid File(s) Found. Failed to repair." in trial version then chance to repair the file in paid version is very less.

Yes, send me some of the files for review purpose.

You can mail your files at following e-mail address:


December 14, 2015 10:19 pm

Hi Amit,

I have the same problem as Ólafur did.
Where you able to help him?
Is there anything I can do?


Amit Pandey
December 15, 2015 02:41 am

Hi Jonas,

We did not received any file from Olafur so we can't do anything without file. Requesting you to sent the file at above mentioned email address. We will review the file and get back to you as soon as possible.

Moinak Mazumdar
December 18, 2015 07:06 pm

Hi Amit,
Thanks for all your post the information's were helpful. I am facing one problem with my SD card, I have 32GB san disk SDHC 10C card which was having almost 8k jpeg files. I was able to recover around 3k files without issue and rest of 5K files were recovered and showing the data size in few MB which is expected, but I couldn't see the preview of the pictures. Then I used a demo version of Stellar JPEG Repair software and after a long running the software return invalid files. These files are very important to me is there a way to get these files back.

Your prompt response would be very helpful.


Amit Pandey
December 21, 2015 03:39 am

Hi Moinak,

Sorry to say that if you get "Invalid File(s)" error using demo version of Stellar JPEG repair then chance to repair the file in paid version is very less.

Please send some of the files for review purpose at above mentioned email address.


Lora Fonacier
January 27, 2016 12:42 pm

Does it only really save repaired files as thumbnails? I thought they can be restored to original form and quality.

Amit Pandey
January 28, 2016 04:51 am

Hi Lora,

JPEG repair software repairs corrupt or damaged files. In case, images are severely corrupted then it can extract the thumbnail of images without compromising its visual fidelity.

February 18, 2016 03:06 pm

Results of JPEG repair are unpredictable. An serously damaged jpg file (2/3 unreadable) was perfectly restored whereas another jpg with a bug on the color table (making a shift on row/colums) has not been repaired (only the thumbnail was properly extracted, with the correct color table). What can I do? Thanks.

Amit Pandey
February 22, 2016 04:37 am

Hi Herve,

Stellar JPEG repair tries to repair all the selected corrupt jpeg files, if it finds any file is badly/severely corrupted then restores the thumbnail of that image.

March 27, 2016 06:21 am

i tried using the demo version to get some jpg files back. i go the feedback ' invalid file'. how dthis be resolved.

Amit Pandey
March 29, 2016 03:36 am

Hi Code,

Sorry to say' as you are getting "Invalid File(s)" error using demo version of software then chance to repair the file in paid version is very less.

Please send some of the files for review purpose at below mentioned email address.



September 17, 2017 04:26 pm

hello dear. sorry to say your soft cant repair my jpg file. show result show invalid file. my file maybe damage by virus. what can i do now. any solution????

December 26, 2017 11:35 pm

as I try to open a jpg file I simply get Invalid Image it shows no preview available the original file become invalid and 0x0 resulosion, what should i do?
does it mean that the picture can not be repaired?

December 27, 2017 12:43 am

As per your concern we will contact you through email.

Warm Regards,
Stellar Data Recovery

Rayan Mustafa
April 13, 2018 02:48 pm

I just purchased the full version of Stella Jpeg Repair and tried to repair many photos more than 100 pictures but it was all " invalid file " though the size of the file still exist as the original ones ..
anyways, as I have read this issue cant be repaired unfortunately ..
I wanna refund and cancel the purchase pls so what is the procedure

April 13, 2018 07:51 pm


Thank you for contacting us.

Please confirm us the order reference number or email address in order to verify the order details.

Further software works on the principle of "What you see, you can recover". It means if you are able to see preview of file in our software, repairing is possible only.

Raja Datta
December 7, 2018 09:00 pm

Hi - I purchased your product for repairing corrupt photos, the thumbnails look great, but the actual picture did not get fixed and instead has the area that was corrupt substituted with gray. Please help as I purchased this and have had no luck with your product.

Stellar Support
December 7, 2018 10:03 pm


Thank you for contacting Stellar Data Recovery.

We would request you to confirm what type of files are you trying to repair. Also confirm if you are able to see the preview of the files.

Hope for your cooperation.

Stellar Data Recovery.

Mark Woudstra
March 3, 2019 11:16 am


I have recovered my photo's. But i can not get a preview. Probably they are damaged. I purchased your program and let it repair. But with most of the pictures i get a message "advance repair". What do i have to do than? i did one photo and it asks to upload a newer one from the same device. The result is that i get a grey picture with nothing on it. Please help me!

Stellar Support
March 4, 2019 07:27 am


Thank you for contacting Stellar Data Recovery.

We would like to inform you that we have replied you on your email. Please check your email.

Hoping for your cooperation.

Stellar Data Recovery.

May 3, 2019 09:17 pm

I recover an XLSX file but the file is damage and I try to recover the content. I execute Excel Repair tool but I think fall in an infinitive loop scanning. How can I solve it, I buy the software only for 3 files, 3 files occurs the same thing.

May 7, 2019 06:01 am


Thank you for contacting Stellar Data Recovery.

We would like to inform you that we have replied you on your email. Please check your email.

Hoping for your cooperation.

Stellar Data Recovery.


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