Hello! I’ve been asked to translate one of my Harlowe adventures (a work in progress) into something that displays well on a phone by a party willing to pay for its development.
My question is, is there a way or place I can test the adventure on a phone? I don’t have my own website to host it. I know I can easily send the adventure and its needed files (it uses images and music) to other computers via Drive to test them on PC, but downloading and opening those files on my phone doesn’t work.
Many peeps use itch.io to host their stuff (you don’t need to publish the project to make it work). Otherwise I’ve used neocities.org in the past. Both are free to use.
The easiest way to check how it looks on a phone is to simulate one on your computer. Use DevTools in Chrome. Nearly identical utilities exist in Edge and Firefox.
Itch.io is a solid choice as well. Set the game to private, then access it on your phone.
Works both as Restricted or Draft 
Yeah, restricted was the word I was looking for. I just figured they could easily show it to anyone else on any device that way.
You can compile the project to a single file eg using nodejs. That would solve some of the problems your phone is having.
If you want to stay on your PC, devtools (aka responsive design in some browsers) as suggested by @rpatten is good quick option for layout/CSS testing. Firefox is nice because you can quickly toggle this with Ctrl + Shift + M .
However responsive design might not find possible issues with cookies, savings, javascript, media, etc. that you would see on a real phone.
Thank you for itch.io. I’ll look into that! If I can later delete the unpublished game – since it is being developed for a third party publisher who would not want it available anywhere else – then that would work.
Yep, you can delete it anytime.
You may well be able to find a browser or some other app that opens an exported HTML file on your phone directly, though I’ve had a little go just now and it’s nowhere near as straightforward as you’d hope. Firefox for Android used to do it but I guess they decided that displaying web pages was too much to ask of a web browser?
One workaround I’ve used in the past is to open Twine in the mobile browser, import the story, and then hit “Play” there. If you include the images/audio as Base64 they should work just fine, though I realise this may not be practical in this particular situation (especially if the combined size of those files would exceed the browser’s local storage capacity). I raise the possibility mostly because your original question specified without having a website and I figured you might welcome an option that doesn’t require hosting anything online in any form.
You can set up your phone to use a proxy that points to a local webserver, and put your game up there. (You don’t necessarily have to run an actual proxy server, though that helps.) This is a bit complicated if you’re not technical. Itch is easier, but it puts your story into a frame, which may not be how you intend to serve it in the long run.