Data saver

Data saver is the switch for people who pay by the megabyte. It doesn’t change a single one of your settings. While the connection is metered, it hides the fetches you’ve told it to hide, and the moment you’re back on Wi-Fi everything you chose is back, untouched. Same trick as Power saving, pointed at the network instead of the battery.

WM Keyboard › Advanced › Data saver

Three answers, not two

Every feature on the screen gets one of three answers:

• Allow. Data saver leaves it alone.
• Ask each time. The feature still works, but it stops happening without you saying so. Open the GIF panel on mobile data and the grid says why it’s empty, with a Use mobile data button under it. Tap that and the feature is allowed for the rest of the session, until the network changes or the keyboard restarts.
• Turn off. The feature is off while data saver is on, and nothing is offered.

The rows in the first group only get two of those. They’re the fetches the keyboard makes on its own, with no panel open, so there’s nobody there to ask. An “ask each time” for a clipboard link preview would either be a notification or a silent no, and neither is worth having.

When it turns on

Trigger	Fires when
Only when I turn it on	never by itself: the manual switch is the whole story
On mobile data or a metered network	the active connection is metered, which covers mobile data and any Wi-Fi you or your carrier marked as metered
Only while roaming	the connection is metered and roaming
Android’s Data Saver is on	you turned on the system-wide Data Saver in Android’s own settings
Any of these	any of the three above

Only when I turn it on is the default, so data saver never holds anything back unless you choose a trigger or turn it on. There’s also a manual Save data now switch that holds on any connection, Wi-Fi included, which is what you want on a phone hotspot that Android thinks is free.

What it can hold back

Fetched on its own (allow or turn off, all off by default except rates):

Feature	What it stops
Link previews	the title and thumbnail fetched for a copied link and for a scanned QR code
Word look-ups	the definition fetched when you select a word. A look-up you tap for in the vocabulary list editor is not held back: one tap, a few kilobytes
Photo backgrounds	refilling the pool of rotating background photos, the largest automatic download the keyboard makes
Weather chip	the forecast behind the weather suggestion
Exchange rates	the rate table for the currency chip and converter. Allowed by default: a few hundred bytes, cached for hours
Add-on updates	re-reading add-on repositories to find new versions

Started by you (all three answers; allowed by default, the same rule as Android’s own Data Saver, which restricts background data and lets what you tap for through; only the two that can move real data ask):

Feature	What it asks about
GIFs and stickers	searching and loading the GIF and sticker grids. Allowed by default. Your own sticker packs are files on the phone, so they always work
Web and image search	search results, the thumbnails an image grid loads, and a camera photo sent to a search site (search by photo on the Web setting). Allowed by default
Animated emoji	fetching the animated version of an emoji. Asks by default: the looping preview in the long-press popup waits for a yes, and pressing Send is the yes
Downloads	language data, dictionaries, emoji keyword packs, add-ons and the on-device speech and language models. Asks by default, since these run to hundreds of megabytes
Cloud AI	chat (on the keyboard and in the app), the Settings assistant, AI actions, AI-tidied dictation and the sticker generator’s online engines that run on a provider’s servers. For the sticker generator, a second press of Generate is the yes, and at Turn off only the phone’s model draws. Asked first, the chat’s Retry and the assistant’s next question are the yes; clearing the assistant’s chat in between takes that back, so its next question is asked about again. Held or asked, a dictated phrase stays as heard. Allowed by default: small payloads, and the roaming trigger is the place to say no. On-device models are never held, because reaching them costs nothing
Online grammar check	Grammar check sending the text to a LanguageTool server, a few kilobytes after each pause in typing. Allowed by default. The one row here with only Allow and Turn off: a check runs on every pause, so there is no single moment to ask. Turned off, Harper still checks English on the phone, and the panel says why other languages wait
Speed test	a run of the Internet speed test, which moves tens to hundreds of megabytes on purpose. Asks by default: the panel says how many megabytes a run is likely to cost, and Run anyway is the yes
Transcription server	voice typing that sends each phrase to your transcription server, about 75 KB for every 30 seconds of speech, compressed as Opus (just under a megabyte to a server that reads only WAV, or before the compression library has been fetched). Allowed by default. At Ask each time the voice panel explains, and pressing the microphone again is the yes

With no connection

WM Keyboard › Advanced › Data saver › Use on-device models offline is a separate question from data saving: not what the keyboard may spend, but what it does when nothing can be sent at all. It is off by default. Turn it on, and three tools that use a server change to the on-device model you downloaded when the phone has no connection, or when the server does not answer:

Tool	Set to	Uses instead
Voice typing	a transcription server	a Whisper model for the language you type in, or else your phone’s own voice typing. A phrase already recorded when the server fails is transcribed by the Whisper model, so it is not lost
AI actions	a cloud provider or a server	your on-device model
Translate	the Online engine	the on-device languages you downloaded

A short message tells you the first time a tool changes to the on-device model, and again after the server has answered in between. Translate also shows On device, offline next to the result. A tool with no model downloaded does what it did before: it shows its own error. AI chat always uses the provider you picked.

Where the old switches went

Two settings used to say a smaller version of this, and both moved here:

• Ask before downloading on mobile data, on the Languages screen, is now the Downloads row set to Ask each time.
• Only download over Wi-Fi, on the AI models screen, is the same row set to Turn off.

Whatever you had set carries over, but both rows only act while data saver is on, and data saver never turns on by itself unless you pick a trigger. The Languages screen keeps a row that points here so it’s still findable from where it used to live.

Add-ons keep their own Only on Wi-Fi switch as well, on the Add-ons screen. Either one holding is enough to skip the automatic refresh.

Details & edge cases

• A yes lasts for the session, not forever. Tapping Use mobile data allows that one feature until the network changes underneath it or the keyboard restarts. It’s an answer about the connection you’re on, so carrying it into next month’s roaming would be answering a question you were never asked.
• One yes covers one feature. Allowing the GIF grid doesn’t allow downloads.
• The settings app asks separately. A download you start from the settings screens shows its own confirmation, with the size, and that yes doesn’t carry into the keyboard either.
• A refused download says why. With Downloads set to Turn off, a download button answers with what held it: mobile data, Wi-Fi that Android counts as metered, a VPN, or, on a connection that isn’t metered at all, the Save data now switch. Marking your Wi-Fi unmetered can’t lift that last one. Open Data saver in the same message goes straight to these rows.
• A running download notices the connection change. A model or feature library download asks again every few megabytes. If the phone moves from Wi-Fi to a connection that turns data saver on, and the Downloads row is set to Turn off, it stops within about 4 MB on each connection and says it is paused. What arrived is kept, and the next attempt carries on from there. At Ask each time it goes on, since you were asked when it started.
• Nothing is rewritten. Data saver is a view of your settings, applied on the way out. Turning it off can’t lose your configuration, because it never touched it.
• Power saving still applies on top. If both are on, either one is enough to hold a fetch back. See Power saving.
• An unknown connection counts as free. In the second before the first network reading lands, nothing is held. It’s better to fetch one photo too many than to have every panel come up refusing to work on a cold start.
• Offline is not the same as metered. With no connection at all, the panels show their own offline errors, unless Use on-device models offline gives them a model to use. Data saver doesn’t claim credit for a fetch the radio was never going to make.

See Network policy for the full list of what each feature fetches and where it goes.