How do I set Web Gallery Image Size

I read a few articles on sites like Hoomaan, but none of them answered my questions. Does anyone know the answer to my question?

please answer.

My question is thaT

 how i can customise built_in web gallery?

As far as I know, there is no way to do this in Lightroom.

The easy solution is to replace the large Web Gallery images, with images at the size you prefer.

1) Export the Web Gallery. The web gallery images are split into 2 folders for 'Thumbnails' and 'Large', in the 'Images' folder. (The large images are approx 1200x800px)

2) From your Library, export the same images normally to a size you prefer, into seperate folder. For example, 750px tall at 72dpi. The Export filename should just be the original filename, same as the filename used in the 'Large' folder.

3) Move the images from this export into the 'Large' folder to replace the images there.

Now check it has worked by opening the index.html in the Web Gallery.

Ok, I have hacked my way through this.   High-level its easy.  But there are a couple of wrinkles.

1.  Export the Web gallery

2.  Rename gallery/images/large to something like  gallery/images/large0  as a backup

3.  Using the same collection, do a File/Export ... gallery/images/large.  Make sure to use just {Filename} in the output filename in the export settings.

4.  Adjust filenames of any virtual copy images (see below)

5.  Edit the index.html to change with  largeWidth and largeHeight parms in the LM.images var near the bottom of the html code.

I wrote a Python script to do step 4.   It just uses PIL to read the larger image sizes; reads the index.html and updates with width and height parms and spits out an index2.html.   Sounds easy peasy.  Well almost.

When that is checked out that all is good, rename it  to replace the index.html

Now for the wrinkles.

1.  The files don't get written in the same order, so the Python code has to use dicts or use some other way do a lookup to match the file names correctly

2.  If the collection includes virtual copy images, they get named differently by the two exports.

     Web export:   image1234_1.jpg

     Library export   image1234-2.jpg

     So the those files need to be renamed

3.  Just an icky detail but the parms are quoted strings and there's some whitespace etc so the parsing of the html is a bit grubby.   Actually the html syntax looks a lot like a Python dict but I couldnt get Python to convert the string on the fly, I seem to have to do it the hard way.

Now I have images that fill the screen.  Yay!

Thanks for all the help.

Are you asking about the Lightroom.adobe website used with Synced images from LR Classic and LR CC Mobile systems?

If you are all those images are Smart Previews.