Format + minify
JSON
Format, validate, and minify JSON locally.
Clean up API responses, config files, or copied JSON before sharing.
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Free online tools — PDF, QR, JSON, JSONL, tiktoken, similarity, extractive Q&A, Parquet, DuckDB SQL, Mermaid, UUID, password, JWT, markdown, and more
Free tools that work for you, not on you. — no ads, no accounts, your data never leaves your device.
Data
Parse, query, diff, and inspect structured data in your browser.
One object per line
JSONL
Validate, format, and minify JSON Lines for fine-tuning and eval sets.
Prep fine-tuning or eval files where each line must be one JSON object.
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Local only
Compare
Diff text, JSON, and YAML side by side.
See what changed between two configs, API payloads, or document drafts.
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No upload
Parquet Peek
Inspect Parquet schema and preview rows without uploading your dataset.
Check column types and sample rows before loading a file into Python or SQL.
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Local SQL
DuckDB SQL
Query CSV, JSON, JSONL, and Parquet files with SQL in your browser.
Run SQL on a CSV or Parquet export without setting up a database server.
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AI & ML
Token counting, embeddings, and local models — no API keys required.
GPT encodings
Token Counter
Count GPT-style tokens for prompts and documents in your browser.
Estimate prompt size before sending text to GPT-style models.
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Local ML
Similarity
Compare text meaning and rank RAG chunks with local embeddings.
Score how alike two texts are, or rank FAQ snippets for a search query.
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Local ML
Extractive Q&A
Pull answer spans from pasted context with a local question-answering model.
Find the exact sentence in a doc that answers a question — not a chatbot reply.
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Security
Tokens, passwords, and identifiers generated locally.
Decode + verify
JWT
Decode JWT headers and payloads. Verify signatures locally.
Inspect a token from your app or IdP and verify it with your secret or public key.
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Local only
Password
Random passwords and diceware-style passphrases.
Create a strong password or passphrase for a new account or API key.
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v1–v7
UUID
Generate v1–v7 UUIDs with namespace hashing and formatting.
Generate IDs for database rows, request tracing, or test fixtures.
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Create
Documents, diagrams, photos, and codes — built and exported on your device.
No upload
PDF Merge
Combine PDFs in your browser. Files never leave your device.
Merge scanned pages, invoices, or exports into one PDF without desktop software.
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Preview + PDF
Markdown
Preview Markdown, open .md files, and export the preview to PDF locally.
Open a README or notes file, check GFM formatting, then download a PDF of the preview.
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Live preview
Mermaid
Render flowcharts, sequence, Gantt, C4, and other Mermaid diagrams.
Draft flow or architecture diagrams as code and export PNG for slides or docs.
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Instant download
QR Code
Generate QR codes for links, WiFi, and text.
Make a scannable code for a URL, WiFi network, or contact details.
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BG remove + crop
Passport Photo
Remove background, crop, and size photos for US and international passports locally.
Cut out a headshot, put it on a white background, and export 2×2 or 35×45 for a visa form.
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