Daily Developer Tools
A growing collection of lightweight, free online tools for developers, testers and analysts. Compare lists, work with JSON, CSV and YAML, test regex, diff text and clean test data without installing anything or sending data to a server.
- All tools run 100% in your browser - great for sensitive data and quick checks.
- Optimized for copy/paste from Excel, CSV, Postman, curl and browser dev tools.
- Designed for software engineers, QA testers, data analysts and product teams.
Magic Box (Smart Paste)
Paste JSON / YAML, JWT, Base64, URL, cURL, Cron, .env, CSV, SQL, or a Unix timestamp and we'll suggest the right tool (with one-click handoff). Everything runs locally in your browser.
Tip: If detection is ambiguous, you'll see multiple suggestions. Choose the one that matches your intent.
Browse all in the Use cases library.
List Comparator
Online list comparison tool for developers and testers. Paste two lists of values (IDs, emails, codes, etc.) and instantly see items only in List 1, only in List 2, common in both, plus per-list duplicates. Supports Excel/CSV paste, case-insensitive comparison, sort toggles and copy-to-clipboard for every result set.
JSON <-> CSV Converter
Smart JSON to CSV and CSV to JSON converter. Paste JSON or CSV into a single input and the tool auto-detects the format. Convert JSON arrays of objects into clean CSV for spreadsheets, or turn CSV data into JSON for APIs and test fixtures. Choose delimiters, download results, and export CSV columns as plain lists that integrate directly with the List Comparator.
JSON <-> YAML Converter
Free online JSON to YAML and YAML to JSON converter. Paste JSON or YAML and the tool auto-detects the format. Convert API responses, configuration files and Kubernetes manifests between JSON and YAML without losing structure. Everything is parsed and converted locally in your browser.
JSON Formatter & Validator
Browser-based JSON formatter and validator for API responses, configuration files and test data. Paste any JSON, validate the syntax, pretty-print with indentation, or minify for compact storage. See quick stats, copy or download the formatted JSON, and send it directly into the JSON <-> CSV converter for further transformation.
YAML Validator
Validate YAML syntax with clear error details (line/column), preview parsed output as JSON, and optionally handle
multi-document YAML (---). Useful for Kubernetes, Helm, CI/CD configs, and app settings.
Regex Generator & Tester
Interactive regular expression generator and tester for quickly validating patterns against sample text. Use presets (email, URL, IPv4) and snippets to build regex, then see matches, capture groups and highlighted results in your browser.
Text Diff & Compare
Side-by-side text and code diff tool for comparing two versions of a file, config or snippet. Highlights unchanged, added, removed and changed lines, with optional word-level differences inside modified lines. Simple options for ignoring case and whitespace make it friendly even for non-technical users.
JWT Decoder
Decode JWT headers and payloads in your browser without sending data to a server. Inspect algorithms, claims and metadata quickly while debugging auth flows. Signature is not verified; use this for inspection only.
JWT & OAuth Security Toolkit
Sign and verify JWTs (HS/RS/ES) and generate OAuth PKCE code_verifier + code_challenge values. Build authorization URLs instantly without sending data anywhere.
Base64 Encoder & Decoder
Convert plain text to Base64 and back. Ideal for testing API payloads, auth headers, and simple binary-to-text encodings without installing any CLI tools.
URL & Payload Encoding Suite
One-stop converter for Base64URL, Hex, Gzip/Deflate, and Querystring payloads. Encode, decode, and swap inputs instantly without leaving the browser.
URL Encoder & Decoder
Quickly encode or decode URL strings when working with query parameters, redirects, and callback URLs.
Handles common form-style encoding where + represents a space.
Hash Generator
Generate MD5, SHA-1, SHA-256 and SHA-512 hashes directly in your browser. Paste text, select algorithms, and copy hex or Base64 digests for API calls, file checksums and debugging.
UUID Generator
Generate version 4 UUIDs / GUIDs using cryptographically secure randomness. Configure count and formatting (uppercase, hyphen-less) and copy IDs in one click.
Password & Token Generator
Generate strong passwords, random tokens and test numbers in your browser. Control length, character sets, alphabets and counts using secure randomness.
Timestamp Converter
Convert Unix epoch timestamps (seconds/milliseconds) to local, UTC, ISO and back. Includes a shareable link feature.
Line Tools (Clean & Transform)
Clean and transform pasted data: trim, remove empty, dedupe, sort, wrap, add prefix/suffix and join with delimiters.
URL Parser & Query Builder
Parse URL parts, edit query params in a grid, rebuild and copy.
cURL Converter
Convert curl commands to Fetch, Axios, Python requests, Java OkHttp, and Node http.
HTTP Headers Parser & Builder
Paste raw headers, edit in a grid, normalize casing, export as JSON/Map, detect duplicates.
Certificate & PEM Tools
Decode X.509 certificates, inspect CSRs, and split PEM bundles locally in your browser.
HAR Sanitizer & Replay Packager
Redact secrets in HAR files and export replay-ready packs (Postman, cURL, fetch).
JSONPath Tester
Extract values from JSON using a practical JSONPath subset, with paths + values output.
.env <-> Properties <-> JSON Converter
Convert between .env, .properties, JSON, and bash export. Sort keys, dedupe, and mask secrets.
Cron Expression Analyzer
Analyze cron expressions, get a readable summary, and preview upcoming run times.
Cron Builder
Build cron expressions with a guided UI and preview upcoming run times before deploying.
SQL IN Clause Builder / Chunker
Paste values and generate IN/NOT IN clauses with quoting, escaping, de-duplication, and chunking.
CSV Viewer / Cleaner
Preview CSV as a table, auto-detect delimiter (comma/tab/semicolon/pipe), trim cells, remove empty rows/columns, and export cleaned CSV.
SQL Formatter (Basic)
Basic SQL formatting with indentation + keyword casing for common statements (SELECT/CTE/INSERT/UPDATE/DELETE).
JSON Diff (Order-insensitive)
Compare JSON payloads ignoring object key order (optional ignore array order). Shows changed paths and values.
JSON Patch & Pointer
Generate/apply JSON Patch operations and work with JSON Pointer paths in one place.
Schema Inspector (JSON)
Infer a lightweight schema from JSON: types, nested properties, array item types, and a flat field list.
JSON Schema Validator
Validate JSON payloads against JSON Schema with Ajv. Includes error paths and one-click schema generation.
SQL Join Builder (Visual)
Build JOIN chains and ON conditions quickly, then generate clean FROM + JOIN SQL.
JSON -> cURL / Postman Snippet Generator
Paste a JSON request definition and generate cURL plus a Postman Collection JSON.
OpenAPI Snippet Extractor
Paste OpenAPI (JSON/YAML) to list endpoints and generate example cURL requests (incl. auth placeholders).
OpenAPI -> Postman Collection Exporter
Paste OpenAPI (JSON/YAML) and export a full Postman Collection (v2.1), optionally grouped by tags.
OpenAPI -> Code Snippets (cURL / Fetch / Axios)
Select an OpenAPI operation and generate a ready-to-use snippet (cURL, Fetch, or Axios).
Daily Developer Tools focuses on fast, practical utilities that solve everyday problems for software teams: comparing environment data, cleaning up API responses, converting JSON to CSV or YAML for reporting, testing regex or validating payloads during debugging.
- No sign-up, no login: open the page and start working immediately.
- Runs entirely in the browser: your JSON, CSV, YAML and list data are not uploaded to a backend.
- Optimized for copy/paste workflows: move quickly between IDEs, Excel, Postman and log files.
- Made for real-world usage: built around tasks developers, QA testers and analysts perform daily.
Pipeline Chaining lets you link multiple tools together without copy/paste. Add output from one tool, then send it directly into the next tool in your workflow, all inside your browser.
- How it works: click Add to Pipeline near a tool output, then open the Pipeline drawer to review steps.
- Send forward: choose Send to... to push a step�s output into another tool and auto-fill inputs.
- Stay organized: reorder steps, remove them, or open a step�s tool to re-run it with updated inputs.
- Privacy-first: steps are stored locally in your browser. Enable Privacy Mode to keep data only in the current tab.
Yes. All current tools are free to use in the browser. In the future, some advanced features or integrations may have paid tiers, but the core utilities will remain free.
No. The tools are implemented as client-side JavaScript. Your JSON, CSV, YAML, regex patterns and list contents stay in your browser tab and are not sent to a backend service.
Pipeline steps are saved locally in your browser (localStorage). You can enable Privacy Mode in the Pipeline drawer to keep pipeline data only in the current tab (sessionStorage), which clears when the tab closes.
Software developers, SDETs and QA engineers, data analysts, support engineers and product managers who need quick, trustworthy browser-based utilities for working with text, lists, JSON, CSV and YAML data.
If you notice a bug, have suggestions for improving an existing tool, or want to request a new utility, please send an email to support@dailydevelopertools.com. I review this inbox periodically and use the feedback to plan future updates.
Daily Developer Tools is a small, evolving collection of utility pages designed to remove friction from everyday engineering work. Instead of installing yet another desktop app or browser extension, you can open a single clean page, paste your data, and get instant results. Ideal for day-to-day dev/test/data workflows, link-sharing with teammates, and quick troubleshooting.