From Pearson Edexcel: Understanding results and grades: a guide for students, parents and carers
Use the following links for each exam board’s provisional results statistics and grade boundaries.
AQA Results Statistics AQA Grade Boundaries
Andrew Taylor, Head of Maths curriculum – My thoughts on GCSE results day 2023
Edexcel Results Statistics Edexcel Grade Boundaries
OCR Results Statistics OCR Grade Boundaries
Eduqas Results Statistics Eduqas Grade Boundaries
WJEC Results Statistics WJEC Grade Boundaries

For GCSE Grade Boundaries for all boards from 2017 – see Mathsbot GCSE maths grade boundaries.
To do a finer analysis and look at individual component results and even marks for each question, centres can register with the appropriate examination board for their enhanced results services. To help your thinking have a look at the tutorials and guides.
AQA Enhanced Results Analyssis
Edexcel ResultsPlus
OCR Active Results
OCR blog: How can you use Active Results and Access to Scripts to understand your results? 10 August 2023
WJEC secure website
Access to Scripts 2023
In 2023, scripts can be accessed free from AQA, Pearson-Edexcel and OCR.

FFT Education Datalab, check their blog for the latest information. See A-Level and other level 3 results 2023: The main trends in grades and entries.
Graham Cumming on Twitter has been crunching the numbers since the results were published.

Student Performance Analysis – National examination figures all subjects