Frequently Asked Questions
General Questions
What is FloSync?
FloSync is a multi-screen content synchronization application for digital signage, video walls, and installations. It displays videos, images, and web pages across multiple screens connected to one computer, or across multiple computers on a network. Video content stays visually aligned.
What platforms does FloSync support?
FloSync is available for:
- macOS (10.15 Catalina and later)
- Windows (10 and later)
What content types does FloSync support?
FloSync supports three content types:
Videos:
- MP4 and M4V (H.264, HEVC/H.265)
- MOV (including Apple ProRes)
- MKV, AVI, WebM, WMV, FLV
Images:
- PNG, JPG/JPEG
- GIF (including animated)
- BMP, TIFF, WebP
- SVG
Web Pages:
- Web addresses
- Local HTML files, including their relative assets
If you have a video that doesn't work, try converting it to MP4 (H.264) format.
Is FloSync open source?
No. The FloSync app is free to download and use, for personal and commercial projects alike, but it is not an open-source project and we do not publish the app's source code.
FloSync does build on open-source components, and we take their licenses seriously. FFmpeg is the main one: it is used under the LGPLv2.1, the notice appears in the app under About FloSync, and the matching source is linked from the download page.
If having the source is a requirement for you, FloSync will not meet it, and that is a fair reason to choose something else. If what you need is software that costs nothing and runs on as many screens as your computer can drive, that is what FloSync is.
Screen & Hardware Questions
How many screens can FloSync support?
FloSync can work with as many screens as your computer supports. Practical limits depend on:
- Your graphics card's output capabilities
- GPU memory and processing power
- Video resolution and bitrate
The number is set by your hardware and your video, not by FloSync. When you run out of display outputs or playback headroom, add another computer and use network sync. How many screens can one computer drive? covers how to work out your own number.
Do I need special hardware?
No special hardware is required. FloSync works with:
- Any screens connected via HDMI, DisplayPort, USB-C, or other standard connections
- Integrated or dedicated graphics
- Consumer or professional screens
For demanding multi-display or high-resolution setups, check your machine's simultaneous-output specification and test the actual content you plan to run. A dedicated graphics card may provide more outputs or more playback headroom, but it is not universally required.
Can I use different resolution screens?
Yes, FloSync works with mixed-resolution setups. However:
- Mirrored mode: Video displays at each screen's native resolution
- Spanned mode: Mixed sizes and resolutions work here too. The image is divided across the arrangement, so each screen shows the part that corresponds to where it sits
How do I create a video wall across multiple computers?
Use Spanned mode combined with Global Canvas Extension and Network Sync:
- Set all computers to Spanned mode
- Configure Global Canvas Extension on each computer to define its position in the wall
- Use Network Sync (server/client) to keep all computers synchronized
- Go Live on all computers
For detailed setup instructions, see Network Sync.
Sync Questions
How accurate is the synchronization?
FloSync is designed to keep playback visually aligned across your screens. For most setups, the default sync settings deliver stable, imperceptible alignment.
Do I need to watch the screens while a show is running?
No, not to keep it synced. FloSync is designed to keep your screens aligned on its own once a show starts. If a screen does drift, Sync Tolerance in Preferences is the setting to check, and Troubleshooting covers what to look for.
Can I sync different videos on different screens?
Yes, as long as every video is the same length. One screen can show a product animation while another shows the text that goes with it, and they stay together. This works across screens on one computer in Independent mode, and across separate computers on the same network.
Export every clip at the same frame rate and the same number of frames. Clips of different lengths each play and loop normally, but they will not hold their timing against one another. On a single computer, the status bar flags a duration mismatch when that happens.
Does sync work with images and web pages?
Only video has a timeline, so only video is synchronized frame by frame. Images hold still and each screen renders its own copy of a web page.
Scene changes are a different thing, and they do stay together. A wall showing images or web pages switches from one scene to the next as one, on every computer.
Does FloSync sync audio?
Audio plays from the primary screen. Secondary screens are muted in Mirrored and Spanned modes to prevent echo. Audio timing follows video timing, so synchronized video means synchronized audio.
Network Sync Questions
How does network sync work?
One computer runs as the "server" and leads playback for the rest. The others connect as "clients" and follow it, staying together on their own for as long as the session runs.
Clients find servers by themselves, so there is no address to type: you start the server on one machine, then pick it from a list on the others. All computers must have the same video file loaded.
What network requirements are there?
- All computers on the same local network, on the same subnet. Sync does not cross a router and does not run over the internet.
- UDP port 9201 open on every computer. If you also want to copy content from the server to the clients, open TCP port 9202 as well.
- The same video loaded on every computer.
Wired Ethernet is the right choice for a video wall, where the screens sit side by side and any difference would show. For screens spread around a building, Wi-Fi is fine. Sync Optimization covers how to decide.
Can I sync over the internet?
FloSync is designed for local network use. For remote locations, use scheduled playback rather than live cross-internet sync.
What if my network is unreliable?
Try more lenient network sync settings in Preferences and prioritize wired connections when possible.
What is Global Canvas Extension?
Global Canvas Extension is a feature for multi-computer video walls. It allows you to define how your local screens fit within a larger "global canvas" spanning multiple computers.
For example, in a 3-computer horizontal wall:
- Left computer: Canvas extends 3840 pixels to the right
- Middle computer: Canvas extends 1920 pixels left and 1920 pixels right
- Right computer: Canvas extends 3840 pixels to the left
Each computer then shows its correct portion of the video.
Mode Questions
When should I use Independent mode?
Use Independent mode when:
- Each screen should show different content
- You want separate audio control per screen
- Screens are in different locations and won't be viewed together
When should I use Mirrored mode?
Use Mirrored mode when:
- All screens should show the same content
- Viewers might see different screens from different positions
- You want simplicity - load once, plays everywhere
When should I use Spanned mode?
Use Spanned mode when:
- Creating a video wall (multiple screens as one large image)
- Content is designed for a wide/tall format across screens
- Screens are physically adjacent
Can I change modes with a video playing?
Yes, you can switch modes at any time when not in live mode. The video will adapt to the new mode immediately.
Note: The mode dropdown is disabled during live mode. Exit live mode first to change display modes.
Go Live Questions
What is Go Live?
Go Live is FloSync's fullscreen presentation mode. When you click Go Live, FloSync creates fullscreen windows on each connected screen and plays your videos in visual sync.
How do I exit live mode?
There are three ways:
- Press ESC in any fullscreen window
- Click anywhere on a fullscreen window
- In Controller mode, click the stop button in the control panel. It reads Stop Controller. In fullscreen Live or Schedule mode, the control panel sits behind the fullscreen windows and isn't reachable this way.
There is no confirmation prompt. Live mode ends as soon as you do any of these.
Can I control playback while in live mode?
On a machine running fullscreen Go Live, the fullscreen windows sit on top of every screen it has, including the one showing the control panel. What you work with there is the keyboard: ESC stops the show, and in Interval mode the arrow keys step through scenes while number keys 1-0 jump straight to scenes 1 through 10.
If you need the control panel in front of you while a show runs, use Controller mode. It runs the show on your connected computers without opening fullscreen windows on the machine you are working at, so the timeline and play/pause controls stay where you can reach them.
Playback Questions
Do videos loop automatically?
Yes. Video loops on its own, which is what digital signage needs. Two looping modes are available in Preferences:
- Seamless, the default. Your video repeats without a visible boundary. It applies to MP4 and MOV files; other formats fall back to standard looping automatically, and nothing on screen tells you when that has happened.
- Standard. The video loops normally.
Both modes play audio.
If you see a brief flicker at the loop point, check two things: that Seamless is selected in Preferences, and that the file is MP4 or MOV. If it is neither, convert it and the flicker goes with it. The three formats recommended in Video Preparation all qualify already.
Can I play a playlist of videos?
FloSync currently plays one video per screen at a time. For rotating content, use Scheduling to switch scenes automatically.
Does FloSync remember my videos?
Yes, FloSync automatically saves references to your loaded videos and restores them on the next launch.
Why does a display box say "File not found"?
The file that was loaded there has been moved, renamed, or deleted since FloSync last saw it. Load the file again from its new location, or load a different one. The status bar counts how many files in the current scene are missing, so you can tell at a glance whether it is one file or all of them.
Audio Questions
Why is there no audio on my secondary screens?
In Mirrored and Spanned modes, audio only plays from the primary screen to prevent echo. This is intentional. Only Independent mode allows separate audio per screen.
How do I enable audio on a screen?
Click the speaker icon on the screen box. In Independent mode, each screen has its own audio toggle. In Mirrored/Spanned modes, the toggle controls the primary screen's audio.
Feature Questions
Can FloSync play images?
Yes! FloSync supports images including:
- PNG, JPG/JPEG, BMP, TIFF, WebP
- Animated GIFs (they loop automatically)
- SVG vector graphics
Can FloSync display web pages?
Yes. Right-click a screen and choose:
- Load Web Page URL... for a page on the web
- Load HTML File... for a local HTML file, which can reference its own images, CSS and scripts from the same folder
Web pages can refresh themselves while a show runs. The choices are Never, Every 15 minutes, Every 30 minutes and Every hour.
Note: When you type a web address, FloSync expects
https://, and assumes it if you leave the scheme off. Web pages cannot be spanned across screens: each screen shows the whole page rather than a slice of it.
Does FloSync support scheduling?
Yes. FloSync has two scheduling modes:
Time-of-Day Mode:
- Divide the day into time scenes with different content
- Configure unique schedules for specific days of the week
- Use "Go Live (Schedule)" to play scheduled content automatically
Interval Mode:
- Content cycles on a duration you choose: 1m, 5m, 10m, 15m, 30m or 1h from the presets, or any whole number of minutes you type
- Cue scenes hold until you move them on yourself, with a keypress or a MIDI trigger
- Keyboard controls during live: arrow keys, number keys 1-0
- Use "Go Live (Beginning)" to start from scene 1
Scenes fade down to black and back up as they change during live playback, in either mode. You can turn that off with the Fade Transitions preference.
Click the schedule icon (agenda/list) in the toolbar to access the schedule panel. Use the calendar and timer icons to switch between modes.
Does FloSync support vertical/portrait screens?
Yes, FloSync works with any screen orientation. Configure your screen rotation in your operating system settings, and FloSync will follow.
Troubleshooting Questions
Which video codec works best for sync?
For best sync performance, use H.264 All-Intra, which works great on all platforms with hardware-accelerated playback and smaller files than other all-intra formats. ProRes LT and DNxHR HQ are also supported alternatives, and both are available on macOS and Windows alike. See the Video Preparation guide for details, sample files to test, and transcoding instructions.
How do I save my configuration to use on another computer?
Use File > Export Configuration... (⌘S on macOS, Ctrl+S on Windows) to save your setup to a .flo file. It holds your schedule, content assignments, display mode, Global Canvas Extension, audio settings and any MIDI mappings you've set up (mappings are saved as part of each scene, so they travel with it). It does not carry your preferences, so sync tolerances and launch-at-login stay on the machine they were set up on.
The .flo file points at your media rather than containing it, so copy your video and image files across as well, along with any local HTML files you're using and the images, CSS and scripts they reference from the same folder. On the other computer, use File > Import Configuration... (⌘O on macOS, Ctrl+O on Windows) to load it. If the files ended up somewhere else, FloSync offers to find them for you. A MIDI mapping only records a channel, message type and the note, controller or program number, not a specific controller model, so if the other computer has a different controller you may need to re-learn the mapping there.
How do I reset FloSync to start fresh?
Use File > Reset All Scenes & Content from the menu bar. A confirmation dialog will appear showing what will be cleared:
- All schedule scenes, in both Time-of-Day and Interval modes
- Content assignments for each display
- Global canvas extension settings
Your preferences (sync tolerances, and so on) are preserved.
How do I completely reset FloSync including preferences?
There is a reset for this built into the app, and it is the one to use:
- Open Preferences and scroll to Danger Zone
- Click Reset, the button beside Reset FloSync, then confirm with Reset & Quit
That clears every preference, your schedules, your content assignments, your global canvas extension settings and your logs, and closes the app. Start it again and you are back to a fresh install.
If you would rather clear the files by hand, choose Help > Open Log Folder first: the folder that opens sits directly inside FloSync's own folder. Then quit FloSync, delete that parent folder, and relaunch.
Why does FloSync need firewall permissions?
Your computers talk to each other over the local network, so your operating system asks for permission the first time. Allow FloSync on UDP port 9201, and on TCP port 9202 as well if you want to copy content from the server to the clients. Without those permissions, network features won't work.
Running several screens from a single computer needs no network access at all.
Where can I find FloSync's logs?
Go to Help > Open Log Folder to access diagnostic logs. Logs are organized by date (folders) and hour (files), and are kept for 7 days. These are helpful when troubleshooting issues or contacting support.
See Troubleshooting - Diagnostic Logs for more details.
What is Controller mode?
Controller mode is a Go Live option that runs the show on your connected computers without opening fullscreen windows on the machine you are working at. It is how you operate a video wall from a control booth and keep the control panel in front of you.
It needs server mode, but you do not have to start that first: choosing Controller mode starts it for you. On a machine already connected to another computer as a client, the Controller option doesn't appear in the Go Live dropdown. Disconnect from the server first, or set Auto Go Live to Controller in Preferences, where FloSync asks you to confirm Switch to Server.
See Controller Mode in Go Live for details.
MIDI Controller Questions
Does FloSync support MIDI controllers?
Yes! FloSync supports MIDI controllers for triggering interval scenes during live performances. You can map any pad or button on your MIDI controller to switch between scenes instantly.
What MIDI controllers work with FloSync?
FloSync works with any MIDI controller that sends Note On, Control Change, or Program Change messages. This includes:
- Novation Launchpad (all models)
- Akai APC (APC40, APC Mini, and MK2 versions)
- Arturia Minilab 3
- Native Instruments Maschine
- Any other MIDI controller with pads or buttons
How do I set up MIDI control?
- Open Preferences, find the MIDI Control section, and turn on Enable MIDI Control
- Select your MIDI device from the dropdown
- In the Schedule Panel, switch to Interval Mode
- Click the Learn MIDI icon on a scene, then press a pad on your controller
- The mapping is saved automatically
A mapping you make here is saved as part of the scene, so it travels with a .flo configuration file to another computer (a different controller model may not have pads in the same places, so you may need to re-learn it there). Mappings do not travel over network sync itself: importing scene content from a connected server does not bring the server's mappings with it.
See the MIDI guide for detailed instructions.
Do the LEDs on my controller light up?
Yes, if your controller has LED-equipped pads, FloSync sends color feedback:
- The active scene's pad lights up brightly
- Other mapped scenes show at lower brightness
- You can customize colors per-scene using the palette icon
LED support varies by controller. Newer controllers like Launchpad X and APC Mini MK2 have full color support, while older models may have limited colors.
Does MIDI work with network sync?
Yes. When using server/client mode, MIDI triggers on the server automatically broadcast to all connected clients. This means you can control a multi-computer video wall from a single MIDI controller.
Note: Clients do not process local MIDI input during live mode - only the server responds to MIDI.
My MIDI controller isn't showing up
Try these steps:
- Click the refresh button in the MIDI device dropdown
- Make sure no other application is using the MIDI device exclusively
- On Windows, ensure the MIDI drivers are installed
- Try disconnecting and reconnecting the controller
Getting More Help
If your question isn't answered here:
- Check the Troubleshooting Guide
- Review other documentation sections
- Get in touch
Have a question that should be in this FAQ? Let us know.