Tools for Technical Writers

BY TOOLS.FUN  ·  MARCH 28, 2026  ·  4 min read

Technical writers balance precision with clarity — documenting APIs, writing runbooks, producing developer guides, and maintaining accuracy across fast-moving codebases. These Tools.Fun utilities handle the small but time-consuming tasks: count characters in a field description, create a clean code screenshot, compare two versions of a doc, or format a JSON example. All free, all browser-based.

Part of the Tools for Developers series. See the hub article for the complete guide.

Character Counter

Count characters, words, sentences, and bytes in any block of text. Essential for writing to specific constraints: meta descriptions (150–160 chars), UI tooltip copy, Twitter/X post limits, Slack notification message limits, and database field descriptions with column-width constraints.

SEO writing: meta descriptions should be 150–160 characters. Page titles should be 50–60 characters. Paste your draft here and hit the exact target before publishing.

Code to Image

Convert code snippets into clean, syntax-highlighted images with a choice of themes and fonts. Use for blog posts, documentation sites that don't support code blocks, PDF guides, Notion pages, and slide decks where embedding a proper code block isn't possible.

Documentation tip: code images are also indexable by search engines as alt text and are immune to copy-paste mangling that afflicts some doc platforms.

Diff Tool

Compare two versions of a document, code sample, config file, or API response side by side. Useful for tracking what changed between doc versions during review cycles, comparing before/after migration examples, and verifying that a code sample in a tutorial still matches a newer API version.

JSON Formatter & Validator

Format JSON examples in API documentation so they're readable and properly indented. Validate sample request/response bodies before publishing to ensure they're syntactically correct — a malformed JSON example in docs creates support tickets.

Doc quality tip: always run your JSON examples through a validator before publishing. An extra comma or missing bracket will be caught immediately by readers who copy-paste into their tools.

URL Encoder / Decoder

Encode URLs in documentation that contain special characters, ensuring links remain clickable and accurate. Decode percent-encoded URLs from API docs and convert them to readable form for plain-text documentation.

QR Code Generator

Generate QR codes for printed documentation, conference handouts, whitepapers, and onboarding guides that link to online versions. QR codes bridge physical documentation with live online resources — useful for printed quickstart cards and help desk knowledge base articles.

RegExp Tester

Verify regex patterns before including them in documentation as examples. Test that documented input validation patterns and search-and-replace examples actually behave as described — incorrect regex examples in tutorials are a common frustration for readers.

Timestamp Converter

Convert Unix timestamps to human-readable dates when documenting APIs that return epoch values. Provides accurate, copy-pasteable examples that readers can verify against their own system time.

Base64 Encoder / Decoder

Decode Base64 values when documenting authentication flows, API key formats, JWT structures, and binary data encoding. Create accurate, readable examples for OAuth tutorials and API credential documentation.

JSON to YAML Converter

Convert JSON config examples to YAML for documentation targeting YAML-first tools (Kubernetes, Helm, GitHub Actions, Ansible). Provide examples in both formats when documenting tools that accept either.

Duplicate Line Counter

Remove duplicate entries from glossary lists, feature comparison tables, and changelog entries. Paste a draft list and instantly identify and remove repeated items before publishing.

Hash Generator

Generate SHA-256 checksums of file download examples for documentation that includes binary asset distribution. Provide verifiable integrity checksums alongside download links — a standard expectation in developer-facing documentation.

Color Converter

Convert brand colour codes between HEX and RGB for design system documentation, CSS custom property references, and style guide articles that must provide values in multiple formats for different audiences.

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