Developer — 458 free online tools

458 free developer tools that run in your browser: JSON editor and parser, JWT decoder, regex tester, diff checker, SQL formatter, and CSV to JSON.

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API Stress Estimator

Estimate the stress on your API under different traffic scenarios and configurations, using an M/M/c queueing model.

VerifiedDeveloper

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JSON Editor

Validate, format, minify, and convert JSON snippets.

VerifiedDeveloper

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CSV to JSON

Convert CSV file or text into JSON format

VerifiedDeveloper

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Text Case Converter

Convert text into sentence, title, upper, lower, camel, snake, and kebab case.

VerifiedDeveloper

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Word & Character Counter

Count words, characters, sentences, paragraphs, and reading time instantly.

VerifiedDeveloper

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URL Encoder Decoder Tool

Encode and decode URLs instantly for safe web usage.

VerifiedDeveloper

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Base64 to Text

Decode Base64 strings into readable UTF-8 text, with padding repair, URL-safe alphabet support and a validity check.

VerifiedDeveloperConverters

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Image to Base64

Convert uploaded images into Base64 data URLs for quick embedding.

VerifiedDeveloper

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QR Generator

Generate QR codes instantly for links, text, and data.

VerifiedDeveloper

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Regex Tester

Test and validate regular expressions instantly with live results.

VerifiedDeveloperAI Tools

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JWT Decoder

Decode JWT header and payload claims instantly in the browser.

VerifiedDeveloper

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Diff Checker

Compare two files and highlight the differences

VerifiedDeveloper

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Markdown Preview

Preview Markdown files

VerifiedDeveloper

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Markdown / HTML Converter

Convert Markdown into HTML and strip HTML back to text.

VerifiedDeveloperText & Writing

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HTML to Markdown Converter

Convert HTML into clean Markdown with GFM tables, links, images, and code blocks.

VerifiedDeveloper

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Color Contrast Checker

Check WCAG contrast ratio for text and background colors.

VerifiedDesign & ColorDeveloper

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Barcode Generator

Generate scannable barcodes from text, product codes, and quick inventory labels.

VerifiedDeveloper

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UUID Generator

Generate secure unique UUIDs instantly for any application.

VerifiedDeveloper

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Unix Timestamp Converter

Convert Unix timestamps to readable local, UTC, and ISO dates.

VerifiedDeveloper

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Unit Converter

Convert 71 units across length, weight, temperature, area, volume, speed, data and time.

VerifiedDeveloperLifestyle

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Text Diff Viewer

Compare text versions side-by-side with word-level highlighting, version history, churn analytics and markdown export.

VerifiedDeveloper

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File Metadata Explorer

Extract and explore detailed metadata from files — images, documents, audio, video, and more. All processing stays in your browser.

VerifiedDeveloper

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Browser Session Analyzer

Analyze browser tab sessions, detect duplicates, categorize domains, and get productivity insights to clean up your browsing.

VerifiedDeveloperProductivity

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2FA Authenticator

Generate secure TOTP two-factor authentication codes in your browser. 100% client-side, works offline, RFC 6238 compatible.

Security & PrivacyDeveloper

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Trusted & SafeAll tools are tested and verified for security.

Always UpdatedWe keep our directory fresh and accurate.

Free to UseMost tools are completely free to use.

Community DrivenBuilt for creators by productivity lovers.

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