Seasonal Effects user guide

Kernvel Seasonal Effects draws snow, confetti, falling leaves and other seasonal effects over your storefront on one fixed, non-interactive canvas. The Free plan keeps every feature the app had before Pro. Pro adds seasonal sound, extra effects and decorations, ready-made scenes and a season calendar. Open the app from Shopify admin and check the result on your own theme and devices.

Start with the Free plan

In Shopify's theme editor, switch on the Seasonal Effects app embed and save the theme. The app's dashboard shows a banner until the embed is detected.
On Effect & look, choose one of the 12 one-click presets or pick from the 30 effects. Tune density, speed, size, wind, colour and palette, or use your own image as the falling particle.
On Decorations, add one of the 8 overlays, such as garland, string lights or bunting.
On Placement & schedule, choose the page templates, whether the effect runs on phones, and an optional start and end date. A page checks the date window when it loads, so an already-open page may need a reload at a boundary.
Every settings page has a live preview that runs the real storefront engine. A successful save publishes your settings to the storefront.

Plans: Free and Pro

Free, $0: 30 effects, 8 decorations, 12 one-click presets, the date window, page targeting, mobile control, custom colours and image, the live preview and the performance controls.
Pro, $5 USD every 30 days: everything in Free, plus seasonal sound, 15 extra effects, 6 extra decorations, 21 scenes, the season calendar, layered and interactive effects, cursor trails, add-to-cart bursts and image packs.

Pro is one flat price with every Pro feature included and no usage tiers. Nothing that was in the app before Pro moved behind it.

Start Pro

Open Plan in the app and start Pro. Shopify asks you to approve the charge, then returns you to the app. Your first Pro subscription starts with a 14-day free trial; the trial is available once per store, including after a reinstall.

You can set up and preview Pro scenes, sound and the calendar before you subscribe. They appear on your storefront only while Pro is active.

Cancel or downgrade

Cancel from the Plan page and confirm. Your storefront switches back to your Free effect, decoration and schedule. Your Pro settings are kept, and they come back if you start Pro again. If Shopify pauses your subscription, Pro effects stop until Shopify reactivates it; the Plan page shows the pause and lets you cancel.

Seasonal sound

Pro includes 14 soundscapes generated in the shopper's browser, with no audio files and nothing third-party: sleigh bells, winter wind, crackling fire, fireworks, Diwali temple bells, lantern chimes for Ramadan and Eid, a Lunar New Year gong, spooky night, birdsong, music box, party poppers, rain, waves and summer crickets. Use the sample player on the Pro effects & sound page to hear each one.

Sound is built to stay out of the way:

It is muted by default. No audio starts until a shopper presses the speaker button. If they turned sound on, it resumes after their first tap or click on the next page.
You set a volume limit, and you choose whether the button sits in the bottom left or bottom right corner.
It is off on phones unless you enable it.
It goes silent while the browser tab is hidden.
It never plays for visitors who ask their device for reduced motion.

Scenes

A scene applies a complete look in one click: the effect, a decoration and a sound, and in most scenes a second layered effect. The 21 scenes are Christmas Eve, Winter wonderland, Northern lights, Halloween night, Autumn harvest, Diwali, Holi, Ramadan, Eid, Lunar New Year, Valentine's, Easter, Spring garden, Mother's Day, Father's Day, Summer nights, Independence Day, Black Friday, Cyber Monday, New Year's Eve and Cosy rainy day. After applying a scene you can change any part of it.

Season calendar

Use Season calendar to plan the year once and let Pro switch scenes on their dates.

Add up to 20 yearly seasons. Each has a name, a start and end date, a scene and its own page and theme-template targeting.
Choose Add a suggested year of holidays to start from a ready list, then edit it.
Dates are read in your Shopify store's timezone, and the page shows which season is active today. A date range can run over New Year.
When two seasons overlap, the first one in your list wins.
A page picks its season when it loads, so an already-open page may need a reload at a season boundary.
Moving holidays such as Diwali, Eid, Ramadan, Lunar New Year, Holi and Easter change date every year. Check those entries once a year.

Pro effects and interaction

15 extra effects: blizzard, northern lights, grand fireworks with trails and heart bursts, floating diyas, sparklers, Holi colour clouds, sky lanterns, moons and stars, red envelopes, rose petals, streamers, price tags, flowers, Father's Day and Easter.
6 extra decorations: icicles, glowing fairy lights, a marigold toran, hanging lanterns, a diya row and a blossom branch.
A second effect layered on the same canvas, with its own density.
Depth layers, wind gusts, and particles that move away from or towards the cursor and touch, or react to scrolling.
Snow that settles along the bottom edge, and gifts, coins and petals that bounce and rest.
Cursor trails and an add-to-cart celebration burst. The burst listens passively and never blocks or delays your theme's cart.
Image packs of up to 6 of your own images, and options to play for a set number of seconds or once per visit.

Performance

The canvas is fixed and accepts no clicks, so it cannot shift your layout. The engine defers startup, caps particles, scales down on phones and low-end devices, pauses when the tab is hidden and respects reduced-motion settings. Pro loads only on stores with Pro active, after the page has loaded, and shares the same canvas and animation loop. When frames run slow it sheds particles. Performance still depends on your theme, device and settings, so check pages your shoppers use.

The app reads no product, order or customer data.

Troubleshooting and help

Nothing shows on the storefront: check that the app embed is switched on and saved, the effect is on, today is inside your date window and the current page template is selected.
Pro effects or sound do not appear: check that Pro is active on the Plan page, then reload the storefront page.
No sound: sound starts only after a shopper presses the speaker button, and stays off on phones unless you enabled it.

Contact support for help.