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Search and browse free online tools for JSON, date and time, encoding, generators, text, and local image processing.
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29 tools organized into 6 focused collections.
Image Tools
5Crop, compress, resize, convert, and watermark images locally without uploading them.
View toolsJSON Tools
11Format, compare, inspect, and convert JSON, CSV, Excel, YAML, typed code, or SQL.
View toolsDate & Time
4Convert Unix timestamps, ISO 8601 values, IANA time zones, and cron expressions.
View toolsEncoding Tools
3Encode Base64 and URLs or inspect JWT payloads locally.
View toolsGenerators
3Generate secure UUIDs, passwords, and file checksums in your browser.
View toolsText Tools
3Convert case, count text, and compare revisions locally.
View toolsSearch all tools
Search by tool name, task, or format.
29 matching tools
Image Optimizer
Free image optimizer with an image compressor and converter for JPEG, PNG, and WebP. Resize and process locally.
Image Compressor
Compress images to 100KB, 200KB, 500KB, or a custom size limit.
Image Cropper
Crop JPEG, PNG, and WebP images with freeform, fixed ratios, or circle crops. Rotate and flip locally.
Background Remover
Remove backgrounds locally with AI and download a transparent PNG.
Image Watermark
Add text or logo watermarks with custom opacity, rotation, position, and tiling.
JSON Formatter
Format, validate, and explore JSON in an interactive tree view.
JSON to TypeScript
Generate readable TypeScript types and interfaces from JSON.
JSON to Go
Generate Go structs with nested types, pointers, and JSON tags.
JSON to Python
Generate typed Python dataclasses from nested JSON data.
JSON to Excel
Export JSON as an XLSX workbook with a named worksheet and numeric or boolean cells.
Excel to JSON
Extract JSON from a selected XLSX worksheet, including dates and saved formula results.
JSON to CSV
Export JSON as delimited UTF-8 text with quoted fields and an optional download BOM.
CSV to JSON
Parse CSV or TSV into JSON, preserving text IDs or optionally converting value types.
JSON to SQL
Convert JSON objects into PostgreSQL, MySQL, or SQLite INSERT statements.
YAML ↔ JSON
Convert common data-oriented YAML to JSON or JSON to readable YAML.
JSON Diff
Compare two JSON documents structurally by object path and array index.
Timestamp Converter
Convert Unix timestamps and readable dates across time zones.
Cron Generator
Build cron expressions visually and preview upcoming runs.
ISO 8601 Converter
Parse ISO 8601 dates into UTC, Unix timestamps, and local time.
Time Zone Converter
Convert local dates and times between IANA time zones and UTC.
Base64
Encode and decode Unicode text as Base64 in your browser.
URL Encoder
Encode and decode URL components or complete URLs with Unicode support.
JWT Decoder
Inspect JWT headers, payloads, and timestamp claims without uploading tokens.
UUID Generator
Generate secure UUID v4 and sortable UUID v7 values.
Hash Generator
Calculate MD5, SHA-256, SHA-384, and SHA-512 hashes for text or files.
Password Generator
Create strong random passwords with secure browser cryptography.
Case Converter
Convert text to camelCase, Title Case, snake_case, kebab-case, and more.
Word Counter
Count words, characters, sentences, paragraphs, bytes, and reading time.
Text Diff
Compare two texts line by line and highlight additions and removals.
Private by default
Work without uploading your input
Current utilities process the values you enter in your browser. Learn what the website does—and does not—collect.
Frequently asked questions
Are OnlineTools free to use?
Yes. The tools in this directory are free to use and do not require an account.
Is the data I enter uploaded to a server?
Current tools process the content you enter locally in your browser. The tool input is not intentionally sent to OnlineTools servers.
Can I use these tools on a phone or tablet?
Yes. Tool pages are responsive, although editors and side-by-side comparisons are usually easier to use on a larger screen.
How can I request another tool?
Use the contact page to describe the task, a sample input, and the output you need.