FLASH TIMER (1–200Hz)
SCREEN FLASH TIMER
The screen flash timer shows a timed black/white flash at a selected Hz.
It can support visual timing checks, camera tests and display experiments.
Fullscreen removes page UI so the flash field is clean.
WHO USES IT?
Camera testers, display reviewers, developers and timing experimenters.
Use it cautiously for short sessions only.
COMMON SEARCHES
screen flash timer • flash frequency test • Hz flash screen
fullscreen flash test • camera flash sync • flicker timing test
FLASHING SAFETY
Do not use if you are sensitive to flashing or flicker.
Avoid use around people who may be photosensitive.
Keep brightness low and sessions short.
Stop immediately if you feel discomfort.
DEVICE GUIDANCE
Phones and OLED screens may heat up at high brightness.
Browsers can throttle timing, especially in low-power mode.
Fullscreen should be launched with a direct tap/click.
USE NOTES
The preview is capped so Page 1 stays usable.
Actual fullscreen timing uses requestAnimationFrame and browser cadence.
For camera tests, compare with P795 Camera Sync Test.
FAQ
Is 200Hz exact? Browser/display cadence can limit visible flashing.
Why capped preview? To reduce accidental intense flashing on the page.
How do I exit? ESC or tap/click anywhere in fullscreen.
COMMON USE CASES
Camera rolling-shutter checks and exposure timing experiments.
Comparing display response under controlled black/white switching.
Simple visual metronome-style testing.
MINI BLOG
Timing depends on browser, GPU and refresh rate.
Safety matters more than maximum frequency.
Camera tests can reveal banding and sync issues.
RELATED TOOLS
P790 Advanced Display Tools • P793 Refresh Rate Test
P795 Camera Sync Test • P760 Screen Testing
Previous: P793 Refresh Test • Next: P795 Camera Sync
BEST PATH
Use P793 Refresh Rate before this page to understand cadence limits.
Use P795 Camera Sync after this page for filming and banding checks.
NAVIGATION
Footer links connect HOME, INDEX, PREVIOUS and NEXT.
The internal pager uses the same button names on every page.
PRIMARY PHRASE
screen flash timer is the main search phrase for Teletext-Tools page 794.
The page provides selected-Hz flashing, capped preview and fullscreen output.
CODE HIGHLIGHT
<title> names the adjustable flash frequency tool.
canonical points to /screen-flash-timer/.
SEARCH INTENT
Users want a simple way to display a visual flash at a chosen frequency.
Page 1 answers that intent with controls, preview, safety and fullscreen start.
FREQUENCY TERMS
Flash frequency test, Hz flash screen and fullscreen flash are key related phrases.
Flicker timing test and black white flash timer support broader intent.
CODE HIGHLIGHT
freqRange controls the selected 1–200Hz value.
freqPill mirrors the chosen frequency in readable Teletext style.
READABILITY
SEO copy is not squeezed beside the live flashing tool.
Large internal panels keep help text readable across desktop, tablet and mobile.
SAFETY FEATURES
The visible preview is capped to reduce accidental intense flashing.
The optional safety confirm requires a second START press before fullscreen.
CODE HIGHLIGHT
PREVIEW_CAP limits the on-page preview to 30Hz.
safeToggle controls the safety confirmation step.
armedOnce tracks whether the user confirmed the warning.
USER BENEFIT
The tool remains practical while keeping warnings and comfort limits visible.
Fullscreen output still uses the selected Hz for testing.
FULLSCREEN VALUE
Fullscreen removes frames and UI around the black/white flash field.
The fullscreen layer remains easy to exit with ESC, tap or click.
CODE HIGHLIGHT
fx is the fixed fullscreen flash layer.
fxCatch catches tap and click exits above the fullscreen field.
stopFX() cancels animation and returns the screen to black.
INTERNAL LINKING
Refresh Rate Test and Camera Sync Test support related tasks.
Footer PREVIOUS goes to P793 and NEXT goes to P795.
SEO SUMMARY
Best folder: /screen-flash-timer/
Canonical URL matches the recommended folder exactly.
Tool stays on Page 1; safety and search help are split across later pages.
KEYWORDS
screen flash timer • flash frequency test • fullscreen flash
Hz flash screen • flicker timing test • camera sync flash
display flash test • black white flash timer
CODE HIGHLIGHT
meta description names capped preview, safety warnings and ESC/tap exit.
robots allows indexing with large preview settings.