The Data Field editor defines and verifies the metric Garmin displays inside an activity. It uses the same project saving and build foundations as the Watch Face editor, with controls specific to activity data.

The header contains the project name, target device, save status, Preview, and Build actions. Changing the target device reruns compatibility checks. Build remains unavailable while a new draft has no saved edit or the selected device is unsupported. On smaller screens, Preview is icon-only and Build is available from the desktop layout.

Project structure

Display contains the primary output and any custom visual layers. Simple presentation keeps one Garmin-managed value. Custom presentation adds editable text, shape, gauge, and image layers.

Formulas define reusable computed values. They can read activity sources, convert units, handle null values, compare thresholds, and keep session or lap state.

Activity sources include current and average speed, heart rate, cadence and average cadence, cycling power, distance, time, ascent, descent, and maximum heart rate. The editor checks each source against the selected watch; a sensor value may still be unavailable during an activity, so set a clear fallback and preview missing-data scenarios.

Zones, Alerts, and FIT fields add activity behavior. Alerts support edge, once-per-session, once-per-lap, and cooldown-controlled while-active behavior. They are validated before generation so issues can point back to the owning range, condition, or FIT field.

Activity preview

The center stage shows the value inside an activity-field region. It is not a watch-face preview. Native/simple presentation delegates final typography and placement to Garmin, while the preview verifies the value, label, unit, scenario, and missing-data state.

Custom presentation uses a visual canvas for full, large, compact, and minimal activity layouts. Click or drag across empty canvas space to select layers; hold Shift to add to the selection. Selected layers move and resize together. Arrow keys nudge the selection, Shift plus an arrow moves farther, and Option/Alt-drag duplicates it. Use the context menu or standard copy, cut, paste, duplicate, delete, and arrange shortcuts for layer actions. Grid, Snap, and Guides help align the layout.

Inspector controls

The inspector follows the current selection:

Primary output: source, formula, label, display unit, and missing-data fallback.
Layer settings: content, style, visibility, lock state, and layout geometry.
Behavior: zones, alert feedback and cooldowns, and FIT fields.
Compatibility: selected-watch support and the minimum Connect IQ API level.

Text edits commit when you press Enter or leave the field. Escape restores the saved value. All controls are available by keyboard and retain visible focus.

Review permissions and compatibility

Select the background, then open Compatibility and choose Review. The full inspector explains the current watch’s support, required Connect IQ API level, permissions, restrictions, and automatic fallbacks. Custom FIT fields, for example, require the FIT Contributor permission.

Choose Add comparison device to open the device picker above the compatibility inspector. Comparison watches do not change the project’s current target; they let you compare support, API requirements, issues, and fallbacks before creating another device version or building.

Preview simulations

The editor footer switches the static sample scenario used while arranging the field. Choose Preview for live playback. On desktop, the Preview controls are movable over the canvas; on smaller screens, they appear in a resizable bottom panel. The canvas toolbar remains available for preview-safe controls.

Running, cycling, and swimming scenarios evolve distance, time, pace, heart rate, cadence, power, calories, and laps where those values apply. Use Easy, Steady, or Tempo to compare coordinated effort levels rather than changing one number in isolation. Paused and reset states remain still, stale sensors retain their last sensor readings, and missing or disconnected sensors keep their unavailable values. Play, pause, or restart the scenario at any time.

Simulation frames are derived from a stable baseline, so the same scenario, pace, and elapsed playback time produce the same values. They do not use motion, location, or private activity history.

Design checks

Resolve blocking compatibility and validation issues before building. Common causes include a source the watch does not expose, an unsupported feedback type, a formula unit mismatch, a custom layout overflow, or a custom FIT field collision.

See Save custom FIT data for FIT-specific rules.