Why are gzip and Brotli sizes different from my server's output?

Compression results depend on the algorithm's quality level and settings. The estimator uses typical defaults, so production numbers may differ slightly depending on how your server or CDN is configured.

Does compression help every file type?

Text-based formats like JSON, HTML, CSS, and JavaScript compress well. Already-compressed binaries such as PNG, JPEG, or ZIP gain little or nothing, which the ratio will reflect.

Is there a size limit?

Because everything runs in your browser, very large files are constrained by available memory. For day-to-day snippets and assets there is effectively no practical limit.

Are my files uploaded anywhere?

No. The content you paste or drop is processed locally in your browser and never sent to a server.

Which compression scheme should I enable?

Brotli usually produces smaller output than gzip for text and is widely supported, but gzip has broader fallback coverage. Compare both ratios here and weigh them against your audience's browser support.

File Size Estimator

Estimate original and compressed (gzip, brotli) sizes for text or files to gauge network transfer impact. Paste text or drop a file below.

Option 1: Upload File

Drag & drop a file or

Option 2: Paste Text

Enter JSON, Base64, or any text data.

Size Estimates

Original and estimated compressed sizes from original image.

Original Size

Gzip Estimate

Brotli Estimate

About File Size Estimator

What a file weighs on disk is not what it costs to ship over the wire. Servers and CDNs almost always send text-based assets compressed with gzip or Brotli, so the number that actually affects your page load is the compressed transfer size — not the raw byte count your editor reports. This estimator shows both, so you can reason about real network impact before you deploy.

Paste a snippet of JSON, HTML, CSS, or JavaScript, or drop in a file, and the tool reports the original size next to its gzip and Brotli equivalents along with the compression ratio. That makes it easy to answer practical questions: will inlining this payload bloat the response, how much does minifying actually save, and is Brotli worth enabling for this kind of content.

Estimation happens entirely in your browser, so nothing you paste leaves your machine. It is meant as a fast sanity check during development rather than a substitute for measuring your production server's exact compression settings.

How to use File Size Estimator

Provide content
Paste text directly into the input or drag and drop a file you want to measure.
Read the sizes
The tool shows the original size alongside its gzip and Brotli compressed estimates.
Compare ratios
Use the compression ratio to judge how much bandwidth compression saves for this specific content.
Decide and optimize
Use the numbers to choose between inlining, minifying, or enabling a particular compression scheme.

Frequently asked questions

JSON Formatter · Beautifier · Validator

Format, minify, sort keys, and validate JSON/JSONC/JSON5 with optional JSON Schema validation. Supports comments and trailing commas.

Base64 Encoder / Decoder

Encode text or files to Base64, or decode Base64 back to its original form. Supports text input and file drag-and-drop.

Zip File Diff Checker

Compare two Zip files and identify differences including added, removed, changed, and unchanged files with detailed metadata.