Can I use this tool to benchmark image sizes before and after compression?

Yes. Run the report on your original assets, compress or convert them, then run the report again on the output. The plain-text format makes it easy to diff the two results.

Does the tool support WEBP files?

Yes. WEBP is a supported input format alongside PNG, JPG, and JPEG. All image files must be 50 MB or under per file.

Is this tool useful for auditing JSON payload sizes for API responses?

Yes. JSON files up to 50 MB are supported. For teams auditing API payload sizes as part of a performance review, the byte-accurate report is more reliable than file explorer estimates.

How many files can I audit in a single batch?

Up to 50 files with a combined limit of 2 GB per batch. For most web asset audits, this covers an entire page or component's asset inventory in one run.

Web Asset Size Audits: Know Every File's Weight Before You Deploy

Page performance depends on asset weight — and web teams can't optimize what they haven't measured. Deliteful's File Size Report tool gives frontend developers and performance engineers an instant, per-asset size inventory for any batch of web files, covering images, JSON, and documents with exact byte counts and human-readable equivalents.

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Core Web Vitals are directly affected by asset sizes. A hero image that's 800 KB instead of 80 KB can single-handedly push Largest Contentful Paint above the 2.5-second threshold. JSON payloads over 50 KB add measurable parse time on mobile devices. Before running an optimization pass — compression, format conversion, lazy loading — teams need a baseline size inventory to measure against. Without one, you are optimizing blind.

Deliteful's File Size Report accepts all common web asset formats: PNG, JPG, JPEG, WEBP, JSON, and more, in batches of up to 50 files. The output is a clean .txt file with raw byte counts and base-1024 human-readable sizes. Use it as a pre-optimization baseline, include it in a performance audit report, or compare before-and-after batches to quantify compression gains.

How it works

1
Sign in with Google
Create your free Deliteful account in 3 clicks — no credit card required.
2
Upload your asset batch
Add up to 50 image, JSON, or document files — mix formats freely.
3
Generate the size report
Deliteful returns a .txt file with each asset's filename, exact byte count, and human-readable size.
4
Use as your optimization baseline
Record pre-optimization sizes, run your compression or format conversion pass, then re-run the report to quantify the improvement.

Frequently asked questions

Can I use this tool to benchmark image sizes before and after compression?: Yes. Run the report on your original assets, compress or convert them, then run the report again on the output. The plain-text format makes it easy to diff the two results.
Does the tool support WEBP files?: Yes. WEBP is a supported input format alongside PNG, JPG, and JPEG. All image files must be 50 MB or under per file.
Is this tool useful for auditing JSON payload sizes for API responses?: Yes. JSON files up to 50 MB are supported. For teams auditing API payload sizes as part of a performance review, the byte-accurate report is more reliable than file explorer estimates.
How many files can I audit in a single batch?: Up to 50 files with a combined limit of 2 GB per batch. For most web asset audits, this covers an entire page or component's asset inventory in one run.

Sign up free with Google and generate a byte-accurate size baseline for your web assets before your next optimization sprint.