filemarkr
All ToolsGuides
filemarkr

60+ free developer tools that run entirely in your browser — JSON formatter, JWT decoder, Base64, diff checker, regex tester, hash generator and more. No upload, no sign-up, completely private.

JSON & Data

  • JSON Formatter
  • JSON Minifier
  • JSON Validator
  • JSON to CSV
  • CSV to JSON
  • JSON to YAML

Encode & Decode

  • Base64 Encode / Decode
  • Base64 to Image
  • Image to Base64
  • URL Encode / Decode
  • HTML Entity Encoder
  • JWT Decoder

Text Tools

  • Text Diff Checker
  • Case Converter
  • Word & Character Counter
  • Slug Generator
  • Remove Duplicate Lines
  • Sort Text Lines

Generators

  • UUID Generator
  • Password Generator
  • Lorem Ipsum Generator
  • QR Code Generator
  • Random Number Generator
  • NanoID Generator

Popular Guides

  • How to Format and Pretty-Print JSON (Without Breaking It)
  • How to Minify JSON and Shrink Your API Payloads
  • How to Validate JSON and Pinpoint the Exact Syntax Error
  • How to Convert JSON to CSV for Excel and Google Sheets
  • How to Convert CSV to JSON (With Proper Header Detection)
  • All guides →

Explore

  • All Tools
  • JSON Formatter
  • JWT Decoder
  • Diff Checker
  • UUID Generator

Company

  • About
  • Privacy
  • Terms
  • Sitemap

Our Promise

  • 100% in your browser
  • Zero uploads
  • No sign-up, always free

© 2026 filemarkr. Designed & developed by Naved Naik.  All processing happens locally in your browser.

All tools

Image to Base64

Turn any image into a Base64 data URI for CSS, HTML or JSON.

100% private Instant, in-browser Read the guide
Loading the tool…

Image to Base64

The image to Base64 tool converts any image into a Base64 data URI you can drop straight into CSS, HTML, or JSON. Inlining small images as data URIs removes an extra HTTP request, which is handy for icons, background sprites, email templates, and self-contained documents. Instead of running a command-line encoder, you can generate the string here in seconds.

How it works

The encoding runs locally in your browser with JavaScript. Select an image and it is read directly from your device and converted into a data:image/...;base64,... string, ready to copy. Nothing is uploaded, which means even though you are choosing a local file, the image is processed in memory and never sent to a server.

Practical use cases

  • Inline a logo or icon into CSS with a background-image data URI.
  • Embed an image in an HTML email or a single-file document.
  • Store a small image as a string inside a JSON config or fixture.
  • Prototype without hosting assets on a separate server.

To decode or preview a Base64 string, use Base64 to Image. For encoding plain text, see Base64 Encode / Decode, and when embedding the result in markup you may find the HTML Entity Encoder useful.

Private by design

Your image is encoded in-browser and is never uploaded. The tool is free, requires no account, and works on all modern browsers including mobile, so you can turn images into Base64 data URIs while keeping your files private on your own device.

Frequently asked questions

Any image your browser can read, including PNG, JPG, GIF, WebP, and SVG, can be converted into a Base64 data URI.

Related tools

Base64 Encode / Decode

Encode text to Base64 and decode it back, with full Unicode support.

Base64 to Image

Preview and download an image from a Base64 or data-URI string.

URL Encode / Decode

Percent-encode and decode URLs and query-string components safely.

HTML Entity Encoder

Encode and decode HTML entities to escape or unescape markup.