The Best Free Browser Tools for Python Developers
Python developers juggle more tools than most. From wrangling JSON APIs and validating regex patterns in Django views, to encoding binary data in FastAPI responses and auditing timestamps in pandas DataFrames — the day-to-day work is full of small but time-consuming tasks. The free browser-based tools on tools.fun are built exactly for these moments: no installs, no signups, just fast answers.
JSON Formatter & Validator
Python's requests library and REST frameworks like Django REST Framework and FastAPI produce and consume JSON constantly. Paste raw API responses directly into the JSON formatter to pretty-print, validate, and explore nested structures. When a json.JSONDecodeError hits your production logs, this tool pinpoints the exact character causing the problem in seconds.
settings.json config files, and inspecting Django fixture exports before loading them.print(response.json()) call and instantly get readable, indented output — no json.dumps(indent=2) required.Regex Tester
Python's re module is powerful but regex patterns are notoriously hard to get right on the first try. The regex tester lets you write your pattern, paste sample text from your actual data, and see matches highlighted live. This is invaluable when building URL routing patterns for Flask or Django, or writing validators for form inputs.
re.compile() patterns before dropping them into production code, writing Django URL patterns, and validating CSV column data with pandas.re module supports them but they're tricky to write blind.Unix Timestamp Converter
Pandas DataFrames often store timestamps as Unix epoch integers. FastAPI and Django models expose ISO 8601 strings. Converting between these formats mentally is error-prone. The timestamp converter handles both directions instantly, including timezone-aware conversions, so you always know exactly what datetime.fromtimestamp(1711584000) actually means.
created_at fields in database exports, verifying JWT exp and iat claims, and checking Jupyter notebook execution timestamps.Base64 Encoder / Decoder
Python's base64 module is straightforward, but context-switching out of a Jupyter notebook just to decode a credential string or an API token is friction you don't need. Paste any base64 string here — including URL-safe variants — and get the decoded value immediately. This is especially useful when working with environment variables loaded from .env files or Kubernetes secrets.
SECRET_KEY encoded configs, and checking base64-encoded binary payloads from ML model APIs.URL Encoder / Decoder
When building query strings manually for requests.get() calls, or debugging a urllib.parse.quote() issue, having a live URL encoder is a huge time-saver. Paste a raw URL with spaces and special characters and get the properly percent-encoded version — or decode a mangled URL from your logs.
Hex Converter
Working with binary data, image buffers, or network packets in Python often means staring at hex strings. The hex converter translates between hex, decimal, binary, and ASCII — useful when debugging struct.pack output, working with PIL/Pillow pixel data, or inspecting raw socket bytes.
List Deduplication Tool
Data cleaning in pandas often starts with removing duplicate values from a column or list. The deduplication tool lets you paste raw lists — one item per line — and strips duplicates instantly. Great for cleaning up user-submitted tag lists, deduplicating log entries, or preparing word lists for NLP preprocessing.
Character & Word Counter
When writing docstrings, README files, or prompt templates for LLM integrations in Python, knowing your character and word count matters. This tool gives you instant counts without opening Word or Google Docs. It's also useful for checking that your meta_description fields hit the right length in Django CMS projects.
Text Diff Tool
Comparing two versions of a config file, a requirements.txt, or a Django migration is something every Python developer does regularly. The text diff tool shows you exactly what changed between two blocks of text, line by line, with color-coded additions and deletions — no Git required.
requirements.txt before and after pip freeze, reviewing Django migration files, and spotting accidental whitespace changes in YAML configs.MD5 Hash Generator
Python's hashlib module makes MD5 easy, but you often just need a quick hash of a string during debugging — for cache keys, ETags, or verifying file checksums. The MD5 tool gives you instant hashes without writing a single line of code.
AES Encryption Tool
When implementing AES encryption in Python using cryptography or PyCryptodome, verifying your output against a known-good reference is critical. Use this tool to encrypt and decrypt test strings, ensuring your Python implementation produces matching ciphertext.
Password Generator
Every Django project needs a strong SECRET_KEY. Every FastAPI deployment needs a JWT signing secret. Stop reusing weak values — use the password generator to create cryptographically strong random strings of any length and character set, then drop them directly into your .env file.
SECRET_KEY values, creating JWT signing secrets, and producing strong API keys for your own services.Crontab Expression Builder
Django management commands often get scheduled with cron. Celery beat tasks use cron-like schedules. Writing and reading crontab expressions like 0 */6 * * 1-5 is unintuitive — the crontab builder translates plain English into correct cron syntax and explains existing expressions in human-readable form.
Bookmark tools.fun and keep it open in a pinned tab. The next time you're deep in a debugging session and need to quickly decode a token, format a JSON blob, or generate a secret key, it's one click away — no context switch required.
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