Every Tool You Need.
One Place.
AI writing, PDF, image, and developer tools. Free to start, private by design.
Transform AI text into natural human writing that reads smoothly in real-world use.
Rewrite weak bullet points, check ATS compatibility, and tailor your resume to any job description. 20 industry templates included.
Writing Tools
10 tools
AI Detector
Analyze text for AI patterns with per-sentence scoring and multi-model analysis.
AI Rewriter
Paraphrase and rewrite content with different tones: formal, casual, concise, or creative.
AI Summarizer
Condense long content into key points, paragraphs, or one-sentence summaries.
Grammar Checker
Find and fix grammar, spelling, and punctuation errors with detailed explanations.
Plagiarism Checker
Check your content for potential plagiarism and ensure originality before publishing.
Story Generator
Turn any idea into a complete story — creative, horror, romance, sci-fi, or children's.
Email Writer
Describe the situation, get a ready-to-send email — professional, outreach, follow-up.
Essay Writer
Generate well-structured argumentative, narrative, expository, and persuasive essays.
AI Translator
Translate text between 33 languages with natural, context-aware AI translation.
Text to Speech
Convert text to spoken audio using browser voices. Zero cost, fully local.
AI Paraphraser
Rephrase text while keeping the original meaning. Multiple tones.
Spell Checker
Find and fix spelling errors with AI-powered context detection.
Punctuation Checker
Fix commas, periods, apostrophes, and semicolons with AI.
Cover Letter Writer
Generate professional cover letters with AI. Three tones.
Blog Post Generator
Generate listicles, how-to guides, opinion pieces, and comprehensive guides.
Social Media Post
Platform-optimized posts for LinkedIn, X, Instagram, Facebook, TikTok.
Essay Checker
Check grammar, spelling, and structure in essays and academic writing.
Handwriting Generator
Convert typed text to realistic handwriting images.
AI Flashcards
Generate study flashcards from any topic. Export to Anki/Quizlet.
PDF Tools
All free, browser-based
Merge PDF
Combine multiple PDFs into one file.
Split PDF
Extract pages or split into parts.
Compress PDF
Reduce file size while keeping quality.
PDF to JPG
Convert PDF pages to images.
JPG to PDF
Convert images to PDF documents.
Word to PDF
Convert Word documents to PDF.
PDF to Word
Extract text to editable .docx.
Excel to PDF
Convert spreadsheets to PDF.
Rotate PDF
Rotate pages to any orientation.
Page Numbers
Add page numbers to PDF files.
Protect PDF
Add password protection to PDFs.
Image Tools
All free, browser-based
Compress Image
Reduce image file size without quality loss.
Convert Image
PNG, JPG, WebP, AVIF — any format.
Resize Image
Scale to any dimension.
Image to Text (OCR)
Extract text from images via OCR.
Remove Background
AI-powered background removal, 100% local.
Crop Image
Crop to exact dimensions or aspect ratios.
Image Upscaler
Enlarge images with AI enhancement.
Add Watermark
Add text or image watermarks.
Flip Image
Flip or mirror images horizontally/vertically.
Developer Tools
14 tools
JSON Formatter
Format, validate & minify JSON.
Base64
Encode & decode Base64.
URL Encode/Decode
Encode & decode URL strings.
Hash Generator
MD5, SHA-1, SHA-256, SHA-512.
Color Picker
HEX, RGB & HSL converter.
Regex Tester
Live pattern matching & groups.
Text Diff
Compare two texts side by side.
Markdown Editor
Write & preview Markdown.
Lorem Ipsum
Generate placeholder text.
CSV to JSON
Convert CSV data to JSON.
JSON to CSV
Convert JSON data to CSV.
JWT Decoder
Decode & inspect JWT tokens.
Timestamp
Unix epoch converter.
Case Converter
camelCase, snake_case, UPPER.
More Tools
SEO, social & utility
How It Works
Open a Tool
Pick the right tool — paste text, upload a file, or enter data.
Process Instantly
Results in seconds. PDF and image tools run in your browser.
Download or Copy
Download files, copy results, or send to another tool.
Frequently Asked Questions
Are these tools really free?
Do I need to create an account?
Is my data stored or shared?
What categories of tools are available?
Can I use these tools on mobile?
How do PDF and image tools handle large files?
Need more power?
Plans from $9.99/mo. Up to 500K words, batch uploads, and priority support.
Coda One offers 100+ free online tools for writing, PDF, image, and developer tasks. AI Writing: humanize AI text, detect AI content, rewrite in 8 tones, summarize, check plagiarism, generate stories and essays, draft emails, and check grammar. PDF: merge, split, compress, and convert between PDF, Word, and images. Image: compress, convert formats, resize, extract text via OCR, remove backgrounds, and crop. Developer: JSON formatter, Base64, hash generator, regex tester, text diff, color picker, URL encoder, and Markdown editor. Plus: video compressor, word counter, QR code generator, text to speech, and password generator. All tools free to try, no signup required.