This free audio video sync test generates a repeating visual flash and audio click so you can compare picture and sound timing directly. Adjust the audio timing in milliseconds or frames until the click and flash appear synchronized on your playback setup.
Start the test, watch the center flash and listen for the click. Use the offset control to move the click earlier or later relative to the visual event.
The test gives your eyes and ears a simple repeated reference: a bright visual pulse and a short audio click. At a zero setting, the browser schedules both around the same test event. Moving the offset changes the requested timing of the click relative to the visual pulse.
If the sound appears to arrive after the flash, move the audio adjustment toward the negative side. If the click seems to occur before the flash, move it toward the positive side. Repeating the pulse makes it easier to compare small timing changes than relying on a single event.
For other hands-on browser utilities, explore Audio Tools for Recording, Mixing, and Ear Training or practice level relationships with the Interactive Online Audio Mixer.
Press Start Sync Test to generate repeating flash and click events.
Concentrate on whether the click appears early, late or aligned.
Move the slider or use the fine 1 ms and 10 ms adjustment buttons.
Compare the final millisecond adjustment with its frame equivalent.
Picture and sound can travel through different processing paths. A display may process video before presenting a frame, while an audio path can introduce its own buffering. The result can be a visible event that does not appear to coincide with its matching sound.
Speech is a familiar example because mouth movement gives you a recognizable visual reference. Percussive events, hand claps and other sharp actions can also make timing differences easier to notice.
The test is useful when comparing playback configurations, checking an editing preview, or simply investigating whether an apparent timing problem changes after an audio or display setting is adjusted.
When your work involves spoken material, you can also explore voiceover recording and Russian voice-over production. For music projects, the instrument recording guide covers another side of the production process.
The flash provides a clear visual event that can be compared with the generated click.
The click is generated through the browser audio system and played through your selected output path.
The selected offset is shown as both elapsed time and its equivalent at the chosen frame rate.
An audio video sync checker works best when the reference events are short and obvious. A long sound or gradual visual transition makes the exact timing point difficult to judge. This test therefore uses a brief click and a high-contrast flash.
The adjustment is displayed in milliseconds because time is the most direct way to describe the difference between the two events. The selected frame rate is then used to show the same adjustment as a frame value. For example, 100 ms corresponds to 2.4 frames at 24 fps and 6 frames at 60 fps.
The frame display can be helpful when you are thinking in terms of a video timeline, while millisecond adjustment provides finer control when the desired value falls between whole video frames.
If you are learning how audio behaves inside a production workflow, try the Mixer Console Simulator. You can also read about mixing and mastering or explore the role of music in creative expression.
Begin at 0 ms and listen to several pulses before changing the setting. If the relationship appears wrong, make a larger adjustment first, then narrow the difference with smaller steps. The ±100 ms buttons are useful for broad movement, while the ±10 ms and ±1 ms controls allow finer comparison.
Avoid changing several parts of the playback chain at the same time. If you switch from speakers to Bluetooth headphones, change a display mode and alter the test offset simultaneously, it becomes difficult to know which change affected what you heard.
It can also be useful to repeat the test after changing only one playback setting. This makes the comparison easier to interpret without assuming that every timing difference originates in the media itself.
You may want to run the test after changing a monitor, television, projector, headphones, speakers, audio interface or playback configuration. Comparing the same flash-and-click sequence before and after a change gives you a consistent reference.
It can also help while checking a workstation used for editing video with dialogue, voiceover or music. The test does not replace frame-accurate inspection of source media, but it can quickly show whether your current playback experience appears noticeably early or late.
Creators preparing for recording may find the First Time Recording Studio Guide useful, while singers can read about typical vocal recording workflow and timing. Artists interested in session preparation can also explore recording confidence and preparation.
In this test, a positive value requests the audio click later than the visual reference. A negative value requests it earlier.
The main control uses milliseconds for fine adjustment, while the calculator continuously displays the equivalent number of frames at the selected FPS.
Wireless audio can involve encoding, transmission and buffering before sound reaches the listener. For a simpler comparison, testing a wired output can remove that wireless path from the setup.
No. The flash and click are generated for the test directly in the browser, so a video or audio file is not required.
Explore audio recording, mixing and mastering services, learn about audio content production, or review recording considerations for blues and country music. Artists planning a focused session from another city can also read the recording travel guide.
Start with a zero offset, compare the flash and click, then make small timing adjustments to investigate your current playback synchronization.
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