Developer01
JSON Fix
Repair malformed JSON and turn it into clean, readable data.
Browser-based utilities
Tools for everyday digital work
Nineteen focused utilities for developers, text work, and images. Your content stays in the browser whenever possible.
19 tools · 3 categories
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Developer
8 toolsDeveloper02
JSON Diff
Compare two JSON documents and inspect added, removed, and changed values.
Developer03
Timestamp Converter
Convert Unix timestamps and local dates while keeping an eye on the current time.
Developer04
JWT Decoder
Decode JWT headers and payloads locally without sending tokens to a server.
Developer05
Base64 Encoder
Encode or decode UTF-8 text with standard and URL-safe Base64.
Developer06
Regex Tester
Test regular expressions, inspect capture groups, and highlight every match.
Developer07
UUID Generator
Generate secure UUID v4 values in batches and validate existing UUIDs.
Developer08
Hash Generator
Calculate SHA-256, SHA-384, or SHA-512 hashes for text and local files.
Text
5 toolsText09
Text Clean
Remove copied rich-text and AI formatting while preserving readable structure.
Text10
Text Diff
Compare text line by line with a clear view of additions and removals.
Text11
Case Converter
Switch text between common writing and programming case styles.
Text12
Line Processor
Clean, sort, reverse, number, prefix, or deduplicate lists of lines.
Text13
Word Counter
Measure words, characters, sentences, lines, reading time, and common terms.
Image
6 toolsImage14
Color Spectrum
Extract dominant colors, inspect pixels, and export palettes from an image.
Image15
Image Compressor
Reduce image file size locally with an adjustable quality setting.
Image16
Image Resizer
Resize images to exact dimensions while optionally preserving aspect ratio.
Image17
Image Format Converter
Convert images between PNG, JPEG, and WebP entirely in the browser.
Image18
Color Contrast Checker
Check foreground and background colors against WCAG contrast targets.
Image19
Image Metadata Remover
Strip EXIF and other metadata by safely re-encoding an image locally.
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Original editorial content
Understand the work behind the tool
Practical explanations, review steps, and limitations for common developer and image workflows.
Developer data
7 min read · Read guide →How to repair invalid JSON without changing its meaning
A careful workflow for fixing JSON syntax, reviewing inferred changes, and validating the result before it returns to an application.
Authentication
8 min read · Read guide →JWT decoding is not JWT verification
Understand what a decoded token can show, what signature verification proves, and which application checks still remain afterward.
Encoding fundamentals
6 min read · Read guide →Base64 is an encoding, not encryption
Learn why Base64 values are readable, how standard and URL-safe alphabets differ, and what to use when security is the real requirement.
About 77 Toolkit
77 Toolkit collects small, useful web tools in one place. Text, tokens, and images are processed locally whenever the browser can do the work, so everyday utilities stay fast and private. Learn how the site is built and maintained.