diff --git a/server/server_race_off_test.go b/server/server_race_off_test.go
new file mode 100644
index 00000000..1ce58819
--- /dev/null
+++ b/server/server_race_off_test.go
@@ -0,0 +1,5 @@
+//go:build !race
+
+package server
+
+const raceEnabled = false
diff --git a/server/server_race_on_test.go b/server/server_race_on_test.go
new file mode 100644
index 00000000..30e30e14
--- /dev/null
+++ b/server/server_race_on_test.go
@@ -0,0 +1,5 @@
+//go:build race
+
+package server
+
+const raceEnabled = true
diff --git a/tools/pgimport/main.go b/tools/pgimport/main.go
new file mode 100644
index 00000000..fb91da27
--- /dev/null
+++ b/tools/pgimport/main.go
@@ -0,0 +1,709 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"net/url"
+	"os"
+	"strings"
+
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/urfave/cli/v2"
+	"github.com/urfave/cli/v2/altsrc"
+	"gopkg.in/yaml.v2"
+	"heckel.io/ntfy/v2/db"
+)
+
+const (
+	batchSize = 1000
+
+	expectedMessageSchemaVersion = 14
+	expectedUserSchemaVersion    = 6
+	expectedWebPushSchemaVersion = 1
+)
+
+var flags = []cli.Flag{
+	&cli.StringFlag{Name: "config", Aliases: []string{"c"}, Usage: "path to server.yml config file"},
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "database-url", Aliases: []string{"database_url"}, Usage: "PostgreSQL connection string"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "cache-file", Aliases: []string{"cache_file"}, Usage: "SQLite message cache file path"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "auth-file", Aliases: []string{"auth_file"}, Usage: "SQLite user/auth database file path"}),
+	altsrc.NewStringFlag(&cli.StringFlag{Name: "web-push-file", Aliases: []string{"web_push_file"}, Usage: "SQLite web push database file path"}),
+}
+
+func main() {
+	app := &cli.App{
+		Name:      "pgimport",
+		Usage:     "SQLite to PostgreSQL migration tool for ntfy",
+		UsageText: "pgimport [OPTIONS]",
+		Flags:     flags,
+		Before:    loadConfigFile("config", flags),
+		Action:    execImport,
+	}
+	if err := app.Run(os.Args); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func execImport(c *cli.Context) error {
+	databaseURL := c.String("database-url")
+	cacheFile := c.String("cache-file")
+	authFile := c.String("auth-file")
+	webPushFile := c.String("web-push-file")
+
+	if databaseURL == "" {
+		return fmt.Errorf("database-url must be set (via --database-url or config file)")
+	}
+	if cacheFile == "" && authFile == "" && webPushFile == "" {
+		return fmt.Errorf("at least one of --cache-file, --auth-file, or --web-push-file must be set")
+	}
+
+	fmt.Println("pgimport - SQLite to PostgreSQL migration tool for ntfy")
+	fmt.Println()
+	fmt.Println("Sources:")
+	printSource("  Cache file:    ", cacheFile)
+	printSource("  Auth file:     ", authFile)
+	printSource("  Web push file: ", webPushFile)
+	fmt.Println()
+	fmt.Println("Target:")
+	fmt.Printf("  Database URL:  %s\n", maskPassword(databaseURL))
+	fmt.Println()
+	fmt.Println("This will import data from the SQLite databases into PostgreSQL.")
+	fmt.Print("Make sure ntfy is not running. Continue? (y/n): ")
+
+	var answer string
+	fmt.Scanln(&answer)
+	if strings.TrimSpace(strings.ToLower(answer)) != "y" {
+		fmt.Println("Aborted.")
+		return nil
+	}
+	fmt.Println()
+
+	pgDB, err := db.OpenPostgres(databaseURL)
+	if err != nil {
+		return fmt.Errorf("cannot connect to PostgreSQL: %w", err)
+	}
+	defer pgDB.Close()
+
+	if authFile != "" {
+		if err := verifySchemaVersion(pgDB, "user", expectedUserSchemaVersion); err != nil {
+			return err
+		}
+		if err := importUsers(authFile, pgDB); err != nil {
+			return fmt.Errorf("cannot import users: %w", err)
+		}
+	}
+	if cacheFile != "" {
+		if err := verifySchemaVersion(pgDB, "message", expectedMessageSchemaVersion); err != nil {
+			return err
+		}
+		if err := importMessages(cacheFile, pgDB); err != nil {
+			return fmt.Errorf("cannot import messages: %w", err)
+		}
+	}
+	if webPushFile != "" {
+		if err := verifySchemaVersion(pgDB, "webpush", expectedWebPushSchemaVersion); err != nil {
+			return err
+		}
+		if err := importWebPush(webPushFile, pgDB); err != nil {
+			return fmt.Errorf("cannot import web push subscriptions: %w", err)
+		}
+	}
+
+	fmt.Println()
+	fmt.Println("Verifying migration ...")
+	failed := false
+	if authFile != "" {
+		if err := verifyUsers(authFile, pgDB, &failed); err != nil {
+			return fmt.Errorf("cannot verify users: %w", err)
+		}
+	}
+	if cacheFile != "" {
+		if err := verifyMessages(cacheFile, pgDB, &failed); err != nil {
+			return fmt.Errorf("cannot verify messages: %w", err)
+		}
+	}
+	if webPushFile != "" {
+		if err := verifyWebPush(webPushFile, pgDB, &failed); err != nil {
+			return fmt.Errorf("cannot verify web push: %w", err)
+		}
+	}
+	fmt.Println()
+	if failed {
+		return fmt.Errorf("verification FAILED, see above for details")
+	}
+	fmt.Println("Verification successful. Migration complete.")
+	return nil
+}
+
+func loadConfigFile(configFlag string, flags []cli.Flag) cli.BeforeFunc {
+	return func(c *cli.Context) error {
+		configFile := c.String(configFlag)
+		if configFile == "" {
+			return nil
+		}
+		if _, err := os.Stat(configFile); os.IsNotExist(err) {
+			return fmt.Errorf("config file %s does not exist", configFile)
+		}
+		inputSource, err := newYamlSourceFromFile(configFile, flags)
+		if err != nil {
+			return err
+		}
+		return altsrc.ApplyInputSourceValues(c, inputSource, flags)
+	}
+}
+
+func newYamlSourceFromFile(file string, flags []cli.Flag) (altsrc.InputSourceContext, error) {
+	var rawConfig map[any]any
+	b, err := os.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+	if err := yaml.Unmarshal(b, &rawConfig); err != nil {
+		return nil, err
+	}
+	for _, f := range flags {
+		flagName := f.Names()[0]
+		for _, flagAlias := range f.Names()[1:] {
+			if _, ok := rawConfig[flagAlias]; ok {
+				rawConfig[flagName] = rawConfig[flagAlias]
+			}
+		}
+	}
+	return altsrc.NewMapInputSource(file, rawConfig), nil
+}
+
+func verifySchemaVersion(pgDB *sql.DB, store string, expected int) error {
+	var version int
+	err := pgDB.QueryRow(`SELECT version FROM schema_version WHERE store = $1`, store).Scan(&version)
+	if err != nil {
+		return fmt.Errorf("cannot read %s schema version from PostgreSQL (is the schema set up?): %w", store, err)
+	}
+	if version != expected {
+		return fmt.Errorf("%s schema version mismatch: expected %d, got %d", store, expected, version)
+	}
+	return nil
+}
+
+func printSource(label, path string) {
+	if path == "" {
+		fmt.Printf("%s(not set, skipping)\n", label)
+	} else if _, err := os.Stat(path); os.IsNotExist(err) {
+		fmt.Printf("%s%s (NOT FOUND, skipping)\n", label, path)
+	} else {
+		fmt.Printf("%s%s\n", label, path)
+	}
+}
+
+func maskPassword(databaseURL string) string {
+	u, err := url.Parse(databaseURL)
+	if err != nil {
+		return databaseURL
+	}
+	if u.User != nil {
+		if _, hasPass := u.User.Password(); hasPass {
+			masked := u.Scheme + "://" + u.User.Username() + ":****@" + u.Host + u.Path
+			if u.RawQuery != "" {
+				masked += "?" + u.RawQuery
+			}
+			return masked
+		}
+	}
+	return u.String()
+}
+
+func openSQLite(filename string) (*sql.DB, error) {
+	if _, err := os.Stat(filename); os.IsNotExist(err) {
+		return nil, fmt.Errorf("file %s does not exist", filename)
+	}
+	return sql.Open("sqlite3", filename+"?mode=ro")
+}
+
+// User import
+
+func importUsers(sqliteFile string, pgDB *sql.DB) error {
+	sqlDB, err := openSQLite(sqliteFile)
+	if err != nil {
+		fmt.Printf("Skipping user import: %s\n", err)
+		return nil
+	}
+	defer sqlDB.Close()
+	fmt.Printf("Importing users from %s ...\n", sqliteFile)
+
+	count, err := importTiers(sqlDB, pgDB)
+	if err != nil {
+		return fmt.Errorf("importing tiers: %w", err)
+	}
+	fmt.Printf("  Imported %d tiers\n", count)
+
+	count, err = importUserRows(sqlDB, pgDB)
+	if err != nil {
+		return fmt.Errorf("importing users: %w", err)
+	}
+	fmt.Printf("  Imported %d users\n", count)
+
+	count, err = importUserAccess(sqlDB, pgDB)
+	if err != nil {
+		return fmt.Errorf("importing user access: %w", err)
+	}
+	fmt.Printf("  Imported %d access entries\n", count)
+
+	count, err = importUserTokens(sqlDB, pgDB)
+	if err != nil {
+		return fmt.Errorf("importing user tokens: %w", err)
+	}
+	fmt.Printf("  Imported %d tokens\n", count)
+
+	count, err = importUserPhones(sqlDB, pgDB)
+	if err != nil {
+		return fmt.Errorf("importing user phones: %w", err)
+	}
+	fmt.Printf("  Imported %d phone numbers\n", count)
+
+	return nil
+}
+
+func importTiers(sqlDB, pgDB *sql.DB) (int, error) {
+	rows, err := sqlDB.Query(`SELECT id, code, name, messages_limit, messages_expiry_duration, emails_limit, calls_limit, reservations_limit, attachment_file_size_limit, attachment_total_size_limit, attachment_expiry_duration, attachment_bandwidth_limit, stripe_monthly_price_id, stripe_yearly_price_id FROM tier`)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+
+	tx, err := pgDB.Begin()
+	if err != nil {
+		return 0, err
+	}
+	defer tx.Rollback()
+
+	stmt, err := tx.Prepare(`INSERT INTO tier (id, code, name, messages_limit, messages_expiry_duration, emails_limit, calls_limit, reservations_limit, attachment_file_size_limit, attachment_total_size_limit, attachment_expiry_duration, attachment_bandwidth_limit, stripe_monthly_price_id, stripe_yearly_price_id) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14) ON CONFLICT (id) DO NOTHING`)
+	if err != nil {
+		return 0, err
+	}
+	defer stmt.Close()
+
+	count := 0
+	for rows.Next() {
+		var id, code, name string
+		var messagesLimit, messagesExpiryDuration, emailsLimit, callsLimit, reservationsLimit int64
+		var attachmentFileSizeLimit, attachmentTotalSizeLimit, attachmentExpiryDuration, attachmentBandwidthLimit int64
+		var stripeMonthlyPriceID, stripeYearlyPriceID sql.NullString
+		if err := rows.Scan(&id, &code, &name, &messagesLimit, &messagesExpiryDuration, &emailsLimit, &callsLimit, &reservationsLimit, &attachmentFileSizeLimit, &attachmentTotalSizeLimit, &attachmentExpiryDuration, &attachmentBandwidthLimit, &stripeMonthlyPriceID, &stripeYearlyPriceID); err != nil {
+			return 0, err
+		}
+		if _, err := stmt.Exec(id, code, name, messagesLimit, messagesExpiryDuration, emailsLimit, callsLimit, reservationsLimit, attachmentFileSizeLimit, attachmentTotalSizeLimit, attachmentExpiryDuration, attachmentBandwidthLimit, stripeMonthlyPriceID, stripeYearlyPriceID); err != nil {
+			return 0, err
+		}
+		count++
+	}
+	return count, tx.Commit()
+}
+
+func importUserRows(sqlDB, pgDB *sql.DB) (int, error) {
+	rows, err := sqlDB.Query(`SELECT id, user, pass, role, prefs, sync_topic, provisioned, stats_messages, stats_emails, stats_calls, stripe_customer_id, stripe_subscription_id, stripe_subscription_status, stripe_subscription_interval, stripe_subscription_paid_until, stripe_subscription_cancel_at, created, deleted, tier_id FROM user`)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+
+	tx, err := pgDB.Begin()
+	if err != nil {
+		return 0, err
+	}
+	defer tx.Rollback()
+
+	stmt, err := tx.Prepare(`
+		INSERT INTO "user" (id, user_name, pass, role, prefs, sync_topic, provisioned, stats_messages, stats_emails, stats_calls, stripe_customer_id, stripe_subscription_id, stripe_subscription_status, stripe_subscription_interval, stripe_subscription_paid_until, stripe_subscription_cancel_at, created, deleted, tier_id)
+		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19)
+		ON CONFLICT (id) DO NOTHING
+	`)
+	if err != nil {
+		return 0, err
+	}
+	defer stmt.Close()
+
+	count := 0
+	for rows.Next() {
+		var id, userName, pass, role, prefs, syncTopic string
+		var provisioned int
+		var statsMessages, statsEmails, statsCalls int64
+		var stripeCustomerID, stripeSubscriptionID, stripeSubscriptionStatus, stripeSubscriptionInterval sql.NullString
+		var stripeSubscriptionPaidUntil, stripeSubscriptionCancelAt sql.NullInt64
+		var created int64
+		var deleted sql.NullInt64
+		var tierID sql.NullString
+		if err := rows.Scan(&id, &userName, &pass, &role, &prefs, &syncTopic, &provisioned, &statsMessages, &statsEmails, &statsCalls, &stripeCustomerID, &stripeSubscriptionID, &stripeSubscriptionStatus, &stripeSubscriptionInterval, &stripeSubscriptionPaidUntil, &stripeSubscriptionCancelAt, &created, &deleted, &tierID); err != nil {
+			return 0, err
+		}
+		provisionedBool := provisioned != 0
+		if _, err := stmt.Exec(id, userName, pass, role, prefs, syncTopic, provisionedBool, statsMessages, statsEmails, statsCalls, stripeCustomerID, stripeSubscriptionID, stripeSubscriptionStatus, stripeSubscriptionInterval, stripeSubscriptionPaidUntil, stripeSubscriptionCancelAt, created, deleted, tierID); err != nil {
+			return 0, err
+		}
+		count++
+	}
+	return count, tx.Commit()
+}
+
+func importUserAccess(sqlDB, pgDB *sql.DB) (int, error) {
+	rows, err := sqlDB.Query(`SELECT a.user_id, a.topic, a.read, a.write, a.owner_user_id, a.provisioned FROM user_access a JOIN user u ON u.id = a.user_id`)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+
+	tx, err := pgDB.Begin()
+	if err != nil {
+		return 0, err
+	}
+	defer tx.Rollback()
+
+	stmt, err := tx.Prepare(`INSERT INTO user_access (user_id, topic, read, write, owner_user_id, provisioned) VALUES ($1, $2, $3, $4, $5, $6) ON CONFLICT (user_id, topic) DO NOTHING`)
+	if err != nil {
+		return 0, err
+	}
+	defer stmt.Close()
+
+	count := 0
+	for rows.Next() {
+		var userID, topic string
+		var read, write, provisioned int
+		var ownerUserID sql.NullString
+		if err := rows.Scan(&userID, &topic, &read, &write, &ownerUserID, &provisioned); err != nil {
+			return 0, err
+		}
+		readBool := read != 0
+		writeBool := write != 0
+		provisionedBool := provisioned != 0
+		if _, err := stmt.Exec(userID, topic, readBool, writeBool, ownerUserID, provisionedBool); err != nil {
+			return 0, err
+		}
+		count++
+	}
+	return count, tx.Commit()
+}
+
+func importUserTokens(sqlDB, pgDB *sql.DB) (int, error) {
+	rows, err := sqlDB.Query(`SELECT t.user_id, t.token, t.label, t.last_access, t.last_origin, t.expires, t.provisioned FROM user_token t JOIN user u ON u.id = t.user_id`)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+
+	tx, err := pgDB.Begin()
+	if err != nil {
+		return 0, err
+	}
+	defer tx.Rollback()
+
+	stmt, err := tx.Prepare(`INSERT INTO user_token (user_id, token, label, last_access, last_origin, expires, provisioned) VALUES ($1, $2, $3, $4, $5, $6, $7) ON CONFLICT (user_id, token) DO NOTHING`)
+	if err != nil {
+		return 0, err
+	}
+	defer stmt.Close()
+
+	count := 0
+	for rows.Next() {
+		var userID, token, label, lastOrigin string
+		var lastAccess, expires int64
+		var provisioned int
+		if err := rows.Scan(&userID, &token, &label, &lastAccess, &lastOrigin, &expires, &provisioned); err != nil {
+			return 0, err
+		}
+		provisionedBool := provisioned != 0
+		if _, err := stmt.Exec(userID, token, label, lastAccess, lastOrigin, expires, provisionedBool); err != nil {
+			return 0, err
+		}
+		count++
+	}
+	return count, tx.Commit()
+}
+
+func importUserPhones(sqlDB, pgDB *sql.DB) (int, error) {
+	rows, err := sqlDB.Query(`SELECT p.user_id, p.phone_number FROM user_phone p JOIN user u ON u.id = p.user_id`)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+
+	tx, err := pgDB.Begin()
+	if err != nil {
+		return 0, err
+	}
+	defer tx.Rollback()
+
+	stmt, err := tx.Prepare(`INSERT INTO user_phone (user_id, phone_number) VALUES ($1, $2) ON CONFLICT (user_id, phone_number) DO NOTHING`)
+	if err != nil {
+		return 0, err
+	}
+	defer stmt.Close()
+
+	count := 0
+	for rows.Next() {
+		var userID, phoneNumber string
+		if err := rows.Scan(&userID, &phoneNumber); err != nil {
+			return 0, err
+		}
+		if _, err := stmt.Exec(userID, phoneNumber); err != nil {
+			return 0, err
+		}
+		count++
+	}
+	return count, tx.Commit()
+}
+
+// Message import
+
+func importMessages(sqliteFile string, pgDB *sql.DB) error {
+	sqlDB, err := openSQLite(sqliteFile)
+	if err != nil {
+		fmt.Printf("Skipping message import: %s\n", err)
+		return nil
+	}
+	defer sqlDB.Close()
+	fmt.Printf("Importing messages from %s ...\n", sqliteFile)
+
+	rows, err := sqlDB.Query(`SELECT mid, sequence_id, time, event, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_deleted, sender, user, content_type, encoding, published FROM messages`)
+	if err != nil {
+		return fmt.Errorf("querying messages: %w", err)
+	}
+	defer rows.Close()
+
+	if _, err := pgDB.Exec(`CREATE UNIQUE INDEX IF NOT EXISTS idx_message_mid_unique ON message (mid)`); err != nil {
+		return fmt.Errorf("creating unique index on mid: %w", err)
+	}
+
+	insertQuery := `INSERT INTO message (mid, sequence_id, time, event, expires, topic, message, title, priority, tags, click, icon, actions, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_deleted, sender, user_id, content_type, encoding, published) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22, $23, $24) ON CONFLICT (mid) DO NOTHING`
+
+	count := 0
+	batchCount := 0
+	tx, err := pgDB.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	stmt, err := tx.Prepare(insertQuery)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	for rows.Next() {
+		var mid, sequenceID, event, topic, message, title, tags, click, icon, actions string
+		var attachmentName, attachmentType, attachmentURL, sender, userID, contentType, encoding string
+		var msgTime, expires, attachmentExpires int64
+		var priority int
+		var attachmentSize int64
+		var attachmentDeleted, published int
+		if err := rows.Scan(&mid, &sequenceID, &msgTime, &event, &expires, &topic, &message, &title, &priority, &tags, &click, &icon, &actions, &attachmentName, &attachmentType, &attachmentSize, &attachmentExpires, &attachmentURL, &attachmentDeleted, &sender, &userID, &contentType, &encoding, &published); err != nil {
+			return fmt.Errorf("scanning message: %w", err)
+		}
+		mid = toUTF8(mid)
+		sequenceID = toUTF8(sequenceID)
+		event = toUTF8(event)
+		topic = toUTF8(topic)
+		message = toUTF8(message)
+		title = toUTF8(title)
+		tags = toUTF8(tags)
+		click = toUTF8(click)
+		icon = toUTF8(icon)
+		actions = toUTF8(actions)
+		attachmentName = toUTF8(attachmentName)
+		attachmentType = toUTF8(attachmentType)
+		attachmentURL = toUTF8(attachmentURL)
+		sender = toUTF8(sender)
+		userID = toUTF8(userID)
+		contentType = toUTF8(contentType)
+		encoding = toUTF8(encoding)
+		attachmentDeletedBool := attachmentDeleted != 0
+		publishedBool := published != 0
+		if _, err := stmt.Exec(mid, sequenceID, msgTime, event, expires, topic, message, title, priority, tags, click, icon, actions, attachmentName, attachmentType, attachmentSize, attachmentExpires, attachmentURL, attachmentDeletedBool, sender, userID, contentType, encoding, publishedBool); err != nil {
+			return fmt.Errorf("inserting message: %w", err)
+		}
+		count++
+		batchCount++
+		if batchCount >= batchSize {
+			stmt.Close()
+			if err := tx.Commit(); err != nil {
+				return fmt.Errorf("committing message batch: %w", err)
+			}
+			fmt.Printf("  ... %d messages\n", count)
+			tx, err = pgDB.Begin()
+			if err != nil {
+				return err
+			}
+			stmt, err = tx.Prepare(insertQuery)
+			if err != nil {
+				return err
+			}
+			batchCount = 0
+		}
+	}
+	if batchCount > 0 {
+		stmt.Close()
+		if err := tx.Commit(); err != nil {
+			return fmt.Errorf("committing final message batch: %w", err)
+		}
+	}
+	fmt.Printf("  Imported %d messages\n", count)
+
+	var statsValue int64
+	err = sqlDB.QueryRow(`SELECT value FROM stats WHERE key = 'messages'`).Scan(&statsValue)
+	if err == nil {
+		if _, err := pgDB.Exec(`UPDATE message_stats SET value = $1 WHERE key = 'messages'`, statsValue); err != nil {
+			return fmt.Errorf("updating message stats: %w", err)
+		}
+		fmt.Printf("  Updated message stats (count: %d)\n", statsValue)
+	}
+
+	return nil
+}
+
+// Web push import
+
+func importWebPush(sqliteFile string, pgDB *sql.DB) error {
+	sqlDB, err := openSQLite(sqliteFile)
+	if err != nil {
+		fmt.Printf("Skipping web push import: %s\n", err)
+		return nil
+	}
+	defer sqlDB.Close()
+	fmt.Printf("Importing web push subscriptions from %s ...\n", sqliteFile)
+
+	rows, err := sqlDB.Query(`SELECT id, endpoint, key_auth, key_p256dh, user_id, subscriber_ip, updated_at, warned_at FROM subscription`)
+	if err != nil {
+		return fmt.Errorf("querying subscriptions: %w", err)
+	}
+	defer rows.Close()
+
+	tx, err := pgDB.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	stmt, err := tx.Prepare(`INSERT INTO webpush_subscription (id, endpoint, key_auth, key_p256dh, user_id, subscriber_ip, updated_at, warned_at) VALUES ($1, $2, $3, $4, $5, $6, $7, $8) ON CONFLICT (id) DO NOTHING`)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	count := 0
+	for rows.Next() {
+		var id, endpoint, keyAuth, keyP256dh, userID, subscriberIP string
+		var updatedAt, warnedAt int64
+		if err := rows.Scan(&id, &endpoint, &keyAuth, &keyP256dh, &userID, &subscriberIP, &updatedAt, &warnedAt); err != nil {
+			return fmt.Errorf("scanning subscription: %w", err)
+		}
+		if _, err := stmt.Exec(id, endpoint, keyAuth, keyP256dh, userID, subscriberIP, updatedAt, warnedAt); err != nil {
+			return fmt.Errorf("inserting subscription: %w", err)
+		}
+		count++
+	}
+	stmt.Close()
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("committing subscriptions: %w", err)
+	}
+	fmt.Printf("  Imported %d subscriptions\n", count)
+
+	topicRows, err := sqlDB.Query(`SELECT subscription_id, topic FROM subscription_topic`)
+	if err != nil {
+		return fmt.Errorf("querying subscription topics: %w", err)
+	}
+	defer topicRows.Close()
+
+	tx, err = pgDB.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	stmt, err = tx.Prepare(`INSERT INTO webpush_subscription_topic (subscription_id, topic) VALUES ($1, $2) ON CONFLICT (subscription_id, topic) DO NOTHING`)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	topicCount := 0
+	for topicRows.Next() {
+		var subscriptionID, topic string
+		if err := topicRows.Scan(&subscriptionID, &topic); err != nil {
+			return fmt.Errorf("scanning subscription topic: %w", err)
+		}
+		if _, err := stmt.Exec(subscriptionID, topic); err != nil {
+			return fmt.Errorf("inserting subscription topic: %w", err)
+		}
+		topicCount++
+	}
+	stmt.Close()
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("committing subscription topics: %w", err)
+	}
+	fmt.Printf("  Imported %d subscription topics\n", topicCount)
+
+	return nil
+}
+
+func toUTF8(s string) string {
+	return strings.ToValidUTF8(s, "\uFFFD")
+}
+
+// Verification
+
+func verifyUsers(sqliteFile string, pgDB *sql.DB, failed *bool) error {
+	sqlDB, err := openSQLite(sqliteFile)
+	if err != nil {
+		return nil
+	}
+	defer sqlDB.Close()
+
+	verifyCount(sqlDB, pgDB, "tier", `SELECT COUNT(*) FROM tier`, `SELECT COUNT(*) FROM tier`, failed)
+	verifyCount(sqlDB, pgDB, "user", `SELECT COUNT(*) FROM user`, `SELECT COUNT(*) FROM "user"`, failed)
+	verifyCount(sqlDB, pgDB, "user_access", `SELECT COUNT(*) FROM user_access a JOIN user u ON u.id = a.user_id`, `SELECT COUNT(*) FROM user_access`, failed)
+	verifyCount(sqlDB, pgDB, "user_token", `SELECT COUNT(*) FROM user_token t JOIN user u ON u.id = t.user_id`, `SELECT COUNT(*) FROM user_token`, failed)
+	verifyCount(sqlDB, pgDB, "user_phone", `SELECT COUNT(*) FROM user_phone p JOIN user u ON u.id = p.user_id`, `SELECT COUNT(*) FROM user_phone`, failed)
+	return nil
+}
+
+func verifyMessages(sqliteFile string, pgDB *sql.DB, failed *bool) error {
+	sqlDB, err := openSQLite(sqliteFile)
+	if err != nil {
+		return nil
+	}
+	defer sqlDB.Close()
+
+	verifyCount(sqlDB, pgDB, "messages", `SELECT COUNT(*) FROM messages`, `SELECT COUNT(*) FROM message`, failed)
+	return nil
+}
+
+func verifyWebPush(sqliteFile string, pgDB *sql.DB, failed *bool) error {
+	sqlDB, err := openSQLite(sqliteFile)
+	if err != nil {
+		return nil
+	}
+	defer sqlDB.Close()
+
+	verifyCount(sqlDB, pgDB, "subscription", `SELECT COUNT(*) FROM subscription`, `SELECT COUNT(*) FROM webpush_subscription`, failed)
+	verifyCount(sqlDB, pgDB, "subscription_topic", `SELECT COUNT(*) FROM subscription_topic`, `SELECT COUNT(*) FROM webpush_subscription_topic`, failed)
+	return nil
+}
+
+func verifyCount(sqlDB, pgDB *sql.DB, table, sqliteQuery, pgQuery string, failed *bool) {
+	var sqliteCount, pgCount int64
+	if err := sqlDB.QueryRow(sqliteQuery).Scan(&sqliteCount); err != nil {
+		fmt.Printf("  %-20s ERROR reading SQLite: %s\n", table, err)
+		*failed = true
+		return
+	}
+	if err := pgDB.QueryRow(pgQuery).Scan(&pgCount); err != nil {
+		fmt.Printf("  %-20s ERROR reading PostgreSQL: %s\n", table, err)
+		*failed = true
+		return
+	}
+	if sqliteCount == pgCount {
+		fmt.Printf("  %-20s OK (%d rows)\n", table, pgCount)
+	} else {
+		fmt.Printf("  %-20s MISMATCH: SQLite=%d, PostgreSQL=%d\n", table, sqliteCount, pgCount)
+		*failed = true
+	}
+}