LocalSheet shows everything in a folder as a sheet of thumbnails, like a photographer's contact sheet. Your files are read by this browser, on this device: nothing is uploaded, and no copy of them is kept once you close the tab.
Opening things
A folder
Pick a folder and everything LocalSheet can show inside it appears, subfolders included. Housekeeping folders are skipped on the way — a NAS's snapshots and thumbnails, trash folders, and installed code like node_modules or .venv — unless you open one of them directly.
Some files
Pick a handful of files instead of a whole folder. Like opening a folder, this replaces whatever is showing.
A web address
Open a file from a web server, or a whole folder of them — the plain list of files a NAS, Apache, nginx or python3 -m http.server shows for a directory. Files are fetched only as you look at them, a little at a time. If the address is on another site, that server has to allow other pages to read it (CORS) before folder listings, PDFs and text can be previewed; photos and video show either way, and you'll be told if something is blocked.
Drag & drop
Drop folders or files anywhere on the window. A link dropped in from another tab, or pasted onto the page, opens as a web address.
Recent
The last few folders and addresses you opened are on the start screen and in the Open menu. After a reload the browser asks once before it reads a folder again. Folders can be remembered in Chrome and Edge; the × beside one forgets it.
Browsing
Layouts
Grid shows even square tiles and is the quickest. Waterfall stacks pictures in columns at their own shape, and Rows fits them into neat full-width rows. Those two check every picture's shape first, so a big folder takes a moment to arrange.
Search
Type part of a name or a folder. With several words, all of them have to match. Put a minus in front of a word to leave it out — beach -sunset — and use quotes to keep a phrase together, as in "summer trip". Press / to jump to the search box and Esc to clear it.
File types
Switch kinds of file on and off. Alt-click one (⌥-click on a Mac) to show only that kind, and again to bring everything back. Hover over one to see how many there are; a faded one isn't in this folder at all.
Sort
By name, date, size, or shuffled. A shuffle stays put while you search and filter; the button beside it shuffles again.
By folder
Splits the sheet into a section for each subfolder, with the folder's name staying at the top while you scroll through it. Shows up when there's more than one folder.
Size
The slider sets how big the thumbnails are. Changing the size, the layout or the window keeps your place; closing the viewer brings you back to the last file you looked at.
On a phone
Once something is open the toolbar folds down to the search box. The sliders button beside it opens everything else, and shows a dot while some kinds of file are hidden.
The viewer
Moving around
Click or tap any file to see it full size. Move through the sheet with the arrows at the sides, the arrow keys, or a swipe. To close, press Esc, click the dark background, or swipe down.
Pictures
Zoom with the scroll wheel, a pinch, a double-click or the slider at the bottom right, then drag to look around. The pictures either side are fetched ahead of time, so stepping through a slow share stays quick.
Video & music
Play with the usual controls. Album covers are shown when a folder has a cover.jpg or folder.jpg, or when a track has one built in.
Documents
PDFs open in the browser's own PDF viewer. Markdown is shown formatted, with a button to see the source, and code is colour-highlighted.
Audiobooks
An .m4b book lists its chapters under the player, and the one playing is highlighted. Click a chapter to jump to it.
Slideshow
Press play at the bottom left, or S, to run through the pictures full screen. Each one stays up for 10 seconds unless you change the number, and you can choose to Cut or Fade between them — with a fade, the second box sets how long it takes. Move the mouse or touch the screen to bring the controls back. Esc ends the show.
Save a copy
Buttons at the top of the viewer open the file in a new tab or download it. On a computer they're on each thumbnail too, when you hover over it.
Shortcuts
/
Search. Esc clears it, and a second Esc leaves the box.
Tab Enter
Move to the thumbnails, and open the one that's selected. The arrow keys then move between thumbnails, and Home and End jump to the first and last.
← →
Previous and next file in the viewer. While a video or song is playing, they skip back and forward five seconds instead.
[ ] ↑ ↓
Previous and next chapter of an audiobook. Going back restarts the chapter that's playing; press again straight away to reach the one before it.
F
Full screen on and off.
S
Start or pause the slideshow.
Esc
Leave full screen, or close the viewer or a panel.
Double-tap
Zoom into a picture, then drag to look around.
Swipe down
Close the viewer.
Good to know
Photos
Anything your browser can show. Safari shows iPhone .heic photos; most other browsers can't, and say so rather than showing a blank.
.jpg .jpeg .png .gif .webp .heic .heif .bmp .tif .tiff .avif .svg
Videos
Each thumbnail is a frame from near the start.
.mp4 .webm .mov .m4v .avi .mkv .ogv .3gp
Audio
Thumbnails show the length and the album cover, where there is one. Only the small part of the file holding the cover is read.
.mp3 .wav .ogg .oga .m4a .m4b .flac .aac .opus .wma .weba
PDFs
The thumbnail is the first page. PDFs take the most work to preview, so on a very big folder it's quicker to switch them off until you need them.
.pdf
Text
Thumbnails show the first few lines.
.txt .md .markdown .logRotated logs count too, as long as the ending is just a number: app.log.1, app.log.2
Code
Thumbnails show the first few lines; colour highlighting happens when you open a file.
.js .jsx .mjs .cjs .ts .tsx .py .rb .go .rs .java .c .h .cpp .cc .cxx .hpp .hh .cs .php .swift .kt .kts .scala .sh .bash .zsh .fish .sql .json .jsonc .yaml .yml .xml .html .htm .css .scss .sass .less .vue .svelte .lua .r .pl .pm .graphql .gql .toml .ini .cfg .conf .gradle .properties .bat .ps1 .psm1 .vb .dart .elm .clj .cljs .cljc .ex .exs .erl .hrl .hs .jl .nim .zig .proto .cmakePlus these names, with or without an ending: Dockerfile, Makefile, Rakefile, Gemfile, Procfile, Vagrantfile
Settings
Your layout, filters, sort, thumbnail size and slideshow timing are remembered in this browser, and carry over to whatever you open next.