Warbler ID, Boxmoor, Hemel Hempstead, Hertfordshire, England, UK (1 Viewer)

[BenjiS]

Taken today (20/07/2023)
Haven't got much idea of what this is, except that it might be a willow warbler, as I saw one of the opposite side of the river (it was taken next to a small river) shortly after the photo'd warbler disappeared




TIA

 

[Bewick]

To me it seems better for a chiffchaff