revite/src/lib/conversion.ts

export function urlBase64ToUint8Array(base64String: string) {
    const padding = "=".repeat((4 - (base64String.length % 4)) % 4);
    const base64 = (base64String + padding)
        .replace(/\-/g, "+")
        .replace(/_/g, "/");
    const rawData = window.atob(base64);

    return Uint8Array.from([...rawData].map(char => char.charCodeAt(0)));
}