KOSF Rebrands As The Bay&#8217;s Greatest Hits 103.7

iHeartMedia has once again rebranded 103.7 KOSF San Francisco as “Classic Hits 103.7” has been passed over for “The Bay’s Greatest Hits 103.7“.

As first indicated in our 10/25 Domain Insight, The move makes the station’s previous positioning statement its primary branding. No on-air lineup changes accompanied the shift as Christie James remains in mornings followed by iHeart’s national Martha Quinn midday show, WXTB Tampa based Big Rig in afternoons, and WNRQ Nashville’s Scuba Steve at night.

The change gives the station its eighth identity in the fifteen years it has carried a variation of Classic Hits. During that time it has gone from “103.7 The Band” to “Oldies 103.7” in April 2011 to “103.7 FM” and then “The Bay’s 103.7” to “Big 103.7” in May 2014. The station narrowed to all-1980s in June 2016 as “103.7 iHeart 80s“, which lasted the longest at just under five years when it became “103.7 80s Plus” in May 2021. The “Classic Hits 103.7” identity followed in August 2024.

KOSF registered a 2.5 share in the September 2026 Nielsen Audio ratings for San Francisco and a 3.9 share in San Jose boosted by Connoisseur Media’s recent move of Classic Rock “98.5 K-Fox” KUFX to HD2 where it has held at a 1.2 share

APR 26	MAY 26	JUN 26	JUL 26	AUG 26	SEP 26	STATION	NAME	FORMAT	OWNER	CUME
4/2-4/29	4/30-5/27	5/28-6/24	6/25-7/22	7/23-8/19	8/20-9/16
9.2	9.3	10.0	10.3	10.2	9.8	KQED-FM	88.5 KQED	Public News/Talk	Northern California Public Broadcasting	693,700
8.7	8.8	8.5	8.9	8.1	8.7	KCBS-AM	All News 106.9 & 740 KCBS	News	Audacy	653,800
4.3	5.3	4.7	4.6	4.7	5.3	KISQ-FM	98.1 The Breeze	Soft AC	iHeartMedia	903,800
4.6	4.8	5.4	5.0	5.2	5.1	KOIT-FM	96.5 KOIT	AC	Connoisseur	1,107,300
4.4	4.7	4.1	3.8	4.0	4.3	KMVQ-FM	99.7 Now	CHR	Connoisseur	730,800
3.3	3.6	3.6	3.5	4.0	4.0	KLLC-FM	Alice @ 97.3	Hot AC	Audacy	757,900
4.4	4.7	4.1	4.2	4.0	3.6	KIOI-FM	Star 101.3	Hot AC	iHeartMedia	716,200
3.8	3.6	3.8	3.5	3.7	3.5	KDFC-FM	Classical California KDFC	Classical	University of Southern California	280,400
3.4	2.4	2.7	3.0	2.7	2.8	KRZZ-FM	93.3 La Raza	Regional Mexican	SBS	328,000
3.2	3.2	3.1	2.8	3.0	2.8	KYLD-FM	Wild 94.9	CHR	iHeartMedia	666,800
2.4	2.5	2.7	2.3	2.9	2.5	KOSF-FM	Classic Hits 103.7	Classic Hits	iHeartMedia	567,800
3.0	3.0	2.9	3.0	2.9	2.4	KITS-FM	Live 105	Alternative	Audacy	540,900
3.0	2.7	2.1	1.8	2.2	2.2	KBRG-FM	Amor 100.3	Spanish Adult Hits	TelevisaUnivision	315,800
1.8	1.6	1.3	1.5	1.6	2.2	KMEL-FM	106.1 KMEL	Rhythmic CHR	iHeartMedia	495,700
1.7	1.8	1.7	1.6	1.4	1.9	KGMZ-FM	95.7 The Game	Sports	Audacy	221,700
1.5	1.5	1.4	1.5	1.8	1.8	KBAY-FM	Bay Country	Country	Connoisseur	337,800
1.1	1.3	1.2	1.3	1.4	1.6	KEZR-FM	Mix 106.5	Hot AC	Connoisseur	324,900
1.2	1.8	1.5	1.2	1.2	1.5	KLVS-FM	107.3 K-Love	Christian AC	K-Love Inc.	208,000
1.5	1.5	1.7	1.7	1.7	1.5	KRBQ-FM	102.1 Jams	Classic Hip Hop	Audacy	374,500
2.0	1.8	2.0	1.8	1.8	1.4	KBLX-FM	102.9 KBLX	Adult R&B	Connoisseur	338,700
1.5	1.3	1.3	1.3	1.5	1.4	KSOL-FM	98.9 y 99.1 Que Buena	Regional Mexican	TelevisaUnivision	254,900
1.1	1.1	1.4	1.4	1.6	1.2	KUSC-FM	Classical California KUSC	Classical	University of Southern California	47,100
0.5	0.5	0.7	1.0	1.0	1.1	KCSM-FM	Jazz 91	Jazz	San Mateo County Community College	122,200
1.3	1.0	0.8	0.9	0.8	1.0	KVVF-FM	Latino Mix 105.7 & 100.7	Rhythmic CHR	TelevisaUnivision	190,200
0.9	0.9	0.8	1.0	0.9	0.7	KALW-FM	91.7 KALW	Public News/Talk	San Francisco Unified School District	100,700
0.4	0.4	0.6	0.7	0.7	0.7	KEXC-FM	KEXP Bay Area	AAA	Friends of KEXP	88,400
0.4	0.3	0.5	0.7	0.7	0.6	KKIQ-FM	101.7 KKIQ	Hot AC	Connoisseur	125,700
0.6	0.8	0.6	0.5	0.6	0.6	KUIC-FM	95.3 KUIC	Hot AC	Connoisseur	141,300
0.6	0.2	0.6	0.4	0.5	0.4	KCSM-FM Stream	Jazz 91	Jazz	San Mateo County Community College	15,900
0.4	0.5	0.6	0.6	0.5	0.4	KWVF-FM	102.7 The Wolf	Classic Hits	Amaturo Sonoma	75,200
0.4	0.3	0.4	0.4	0.6	0.4	KZST-FM	100.1 KZST	AC	Amaturo Sonoma	114,400
			0.3	0.3	0.3	KLLC-FM HD2	Channel Q	LGBTQ+ Dance	Audacy	28,800
1.6	1.8	1.9	2.1	0.3	0.3	KUFX-FM HD2	98.5 The Fox	Classic Rock	Connoisseur	29,300
0.2	0.3	0.2	0.2	0.1	0.2	KFGY-FM	Froggy 92.9	Country	Amaturo Sonoma	34,600
			0.2	0.1	0.2	KHTH-FM	Hot 101.7	CHR	Amaturo Sonoma	45,000
0.5	0.2	0.2	0.2	0.1	0.2	KJOR-FM	La Mejor 104.1	Classic Spanish AC	Lazer	14,900
0.1	0.2	0.2	0.2	0.3	0.2	KJZY-FM	Jazzy 93.7	Adult Standards	Redwood Empire	22,600
0.3	0.3	0.3	0.3	0.3	0.2	KSRO-AM	KSRO	News/Talk	Amaturo Sonoma	18,100
0.3	0.3	0.4	0.6	0.2	0.2	KXZM-FM	Radio Lazer 93.7	Regional Mexican	Lazer	48,800
			0.1	0.1	0.1	KBLX-FM HD2	Old School 102.9	Rhythmic AC	Connoisseur	16,600
			0.1	0.1	0.1	KIOI-FM HD2	Pride Radio	LGBTQ+ Dance	Audacy	26,600
			0.1	0.1	0.1	KMVQ-FM HD2	Pulse Radio	LGBTQ+ Dance	Connoisseur	12,600
			0.1	0.1	0.1	KOIT-FM HD2	Highway 1 Radio	AAA	Connoisseur	30,100
			0.2	0.2	0.1	KVRV-FM	97.7 The River	Classic Rock	Amaturo Sonoma	47,000
				0.1		KJZY-FM HD2	99.1 The Bull	Classic Country	Redwood Empire	8,400
Classic Rock KUFX began simulcasting Country KBAY on July 22. The Classic Rock format moved to KUFX-HD2.

APR 26	MAY 26	JUN 26	JUL 26	AUG 26	SEP 26	STATION	NAME	FORMAT	OWNER	CUME
4/2-4/29	4/30-5/27	5/28-6/24	6/25-7/22	7/23-8/19	8/20-9/16
7.5	6.6	5.8	5.4	6.4	6.8	KBRG-FM	Amor 100.3	Spanish Adult Hits	TelevisaUnivision	162,200
5.3	4.5	4.7	5.9	5.8	6.0	KCBS-AM	All News 106.9 & 740 KCBS	News	Audacy	153,400
3.5	4.8	3.9	4.6	4.7	5.4	KEZR-FM	Mix 106.5	Hot AC	Connoisseur	244,900
5.1	6.3	5.4	4.6	5.0	5.4	KIOI-FM	Star 101.3	Hot AC	iHeartMedia	212,500
3.7	3.6	4.4	4.1	4.6	5.4	KOIT-FM	96.5 KOIT	AC	Connoisseur	244,300
3.8	4.2	3.4	4.1	4.9	5.1	KBAY-FM	Bay Country	Country	Connoisseur	185,500
5.0	4.8	3.7	3.2	3.2	3.9	KMVQ-FM	99.7 Now	CHR	Connoisseur	173,000
2.3	2.5	2.5	2.9	4.1	3.9	KOSF-FM	Classic Hits 103.7	Classic Hits	iHeartMedia	143,400
2.6	2.9	2.5	2.7	3.1	3.3	KLLC-FM	Alice @ 97.3	Hot AC	Audacy	137,400
2.5	2.9	2.8	3.0	2.9	3.2	KISQ-FM	98.1 The Breeze	Soft AC	iHeartMedia	163,500
3.7	3.4	3.4	3.0	3.4	3.0	KYLD-FM	Wild 94.9	CHR	iHeartMedia	150,800
3.2	2.5	2.5	2.7	3.7	2.9	KSOL-FM	98.9 y 99.1 Que Buena	Regional Mexican	TelevisaUnivision	89,300
2.5	3.1	3.0	2.7	2.6	2.1	KITS-FM	Live 105	Alternative	Audacy	139,700
1.5	1.6	1.4	1.3	1.2	1.5	KGMZ-FM	95.7 The Game	Sports	Audacy	38,800
1.3	0.9	0.8	0.8	0.8	1.5	KVVF-FM	Latino Mix 105.7 & 100.7	Rhythmic CHR	TelevisaUnivision	63,200
1.3	1.3	1.6	1.1	1.5	1.4	KRBQ-FM	102.1 Jams	Classic Hip Hop	Audacy	77,300
1.0	1.0	1.7	1.6	1.5	1.4	KRZZ-FM	93.3 La Raza	Regional Mexican	SBS	68,400
1.3	1.2	1.2	1.3	1.4	1.2	KMEL-FM	106.1 KMEL	Rhythmic CHR	iHeartMedia	91,000
4.4	4.5	5.3	6.4	1.2	1.2	KUFX-FM HD2	98.5 K-Fox	Classic Rock	Connoisseur	23,500
1.0	1.0	0.9	0.8	0.9	1.1	KBLX-FM	102.9 KBLX	Adult R&B	Connoisseur	62,200
0.9	1.0	1.6	2.4	0.9	0.8	KXZM-FM	Radio Lazer 93.7	Regional Mexican	Lazer	37,500
0.4	0.4	0.6	0.5	0.6	0.6	KWAI-FM	97.7 Air1	Worship	K-Love Inc.	24,800
0.4	0.3	0.3	0.3	0.3	0.5	KJLV-FM	95.3 K-Love	Christian AC	K-Love Inc.	28,200
0.1	0.1	0.2		0.2	0.2	KIOI-FM HD2	Pride Radio	LGBTQ+ Dance	iHeartMedia	11,800
					0.2	KLLC-FM HD2	Channel Q	LGBTQ+ Dance	Audacy	9,300
	0.1		0.2			KMVQ-FM HD2	Pulse Radio	Dance	Audacy	3,400
0.1	0.1	0.2	0.2	0.3		KOIT-FM HD2	Highway 1 Radio	AAA	Connoisseur	8,400
		0.2	0.2			KSFN-AM	Radio Lazer 99.3 / 1510	Regional Mexican	Lazer	1,900
			0.2			KUFX-FM HD2 Stream	98.5 K-Fox	Classic Rock	Connoisseur	0
Classic Rock KUFX began simulcasting Country KBAY on July 22. The Classic Rock format moved to KUFX-HD2.