Test string templates with {{variable}} placeholders against JSON variables. Everything runs locally in your browser — nothing is uploaded.
Test GraphQL queries with variables. Format queries and variables, and preview formatted responses for development and debugging.
Format and beautify GraphQL variables JSON with proper indentation. Ensure your variables are correctly structured before sending queries.
Pretty-prints raw JSON with configurable indent width, key sorting, and bracket collapsing options while flagging syntax errors with exact.
Analyze CSV, generate CSV data, query JSON with path expressions, compare JSON diffs, minify JSON, sort CSV, view JSON tree, and preview CSV tables.
Counts characters with and without spaces and compares your text against platform-specific limits — Twitter/X posts (280), SMS messages (160), SEO meta descriptions (160), Facebook posts (63,206), and LinkedIn summaries (2,600). Real-time counting with space/no-space toggle.
String Template Tester lets you test string templates with {{variable}} placeholders against JSON variables. Everything runs locally in your browser — nothing is uploaded.. It works on any device with a modern web browser.
Test string templates with {{variable}} placeholders against JSON variables. Everything runs locally in your browser — nothing is uploaded. It runs entirely in your browser — no software installation or data uploads required.
Direct text entry, file upload, or URL-based input — depending on the tool. Paste or type your content directly into the provided editor area.
Yes. After the initial page load, String Template Tester runs entirely on your device with no internet connection needed. All processing is done locally.
Tools cover JavaScript, CSS, HTML, SQL, Python, JSON, XML, CSV, and more. Check individual tool descriptions for specifics.
No. All code processing — formatting, minification, conversion, hashing — runs locally in your browser.
Yes. Since processing is local, performance depends on your device. Most operations handle large files without issue.
Yes. SQL uses sql-formatter, JSON uses native JSON.parse, and other formatters follow widely adopted formatting rules.
Yes. All developer tools work fully offline after the initial page load.
Time Converter
Convert between time units including seconds, minutes, hours, days, weeks, months, and years with precise decimal results.
Random Port Generator
Generate random TCP/UDP port numbers from well-known, registered, or dynamic ranges. Useful for network testing, Docker port mapping, and firewall configuration.
Chmod Calculator
Convert between numeric (755) and symbolic (u=rwx,g=rx,o=rx) chmod permission formats. See detailed breakdown for owner, group, and others.
Docker Run to Compose Converter
Convert docker run commands to docker-compose.yml format. Supports ports, volumes, environment variables, networks, restart policies, and container names.
Email Normalizer
Normalize email addresses by removing dots (Gmail), stripping +tags, and lowercasing. Process multiple emails at once for deduplication and cleaning.
Diff Checker
Compares two input texts side-by-side, highlighting inserted, deleted, and changed lines with distinct background colors.