IT & Developer tools
Local tools for crypto, data conversion, web, IPv4 networks and text.
Browse by category
PDF & documents
Merge, split, convert, sign and organize your documents.
Image tools
Compress, resize, convert and remove image metadata.
Product images & UTM
Prepare product images and build campaign tracking links.
Text & data
Count words, change text case and convert CSV or JSON.
IT & Developer tools
Local tools for crypto, data conversion, web, IPv4 networks and text.
Video tools
Trim, convert and compress video on your device.
Audio tools
Trim audio, adjust volume and export MP3 or WAV.
AI tools
Explore PDF text, summarize and translate with supported on-device AI.
Wheel & Draws
Spin a wheel, draw numbers or select winners from your list.
All tools in this category
Format JSON
Validate, format, minify and sort JSON keys.
Base64
Encode or decode Unicode text with Base64.
Password generator
Generate passwords with your chosen length and character sets.
URL encode / decode
Encode Unicode text as a URL component or decode percent escapes.
UUID v4 generator
Generate random UUID v4 identifiers individually or in batches.
SHA-256 hash
Calculate a SHA-256 checksum from UTF-8 text or a local file.
JWT reader
Inspect JWT header and payload locally, without verifying its signature.
Regex tester
Test JavaScript regular expressions and inspect match positions and groups.
Compare code / text
Find added, removed and unchanged lines between two versions of text.
Unix timestamp converter
Convert Unix timestamps to dates or ISO dates to seconds and milliseconds.
Number base converter
Number base converter with local processing, input validation and downloadable results.
URL parser
URL parser with local processing, input validation and downloadable results.
IPv4 subnet calculator
IPv4 subnet calculator with local processing, input validation and downloadable results.
HEX / RGB / HSL
HEX / RGB / HSL with local processing, input validation and downloadable results.
Roman numeral converter
Roman numeral converter with local processing, input validation and downloadable results.
URL slug generator
URL slug generator with local processing, input validation and downloadable results.
Text case converter
Text case converter with local processing, input validation and downloadable results.
Sort / deduplicate lines
Sort / deduplicate lines with local processing, input validation and downloadable results.
Random token generator
Random token generator with local processing, input validation and downloadable results.
HMAC-SHA256 generator
HMAC-SHA256 generator with local processing, input validation and downloadable results.
Text / binary converter
Text / binary converter with local processing, input validation and downloadable results.
JSON minifier
JSON minifier with local processing, input validation and downloadable results.
Coming later
No tools found. Try another search.
IPv4 subnet calculator
IPv4 subnet calculator with local processing, input validation and downloadable results.
Input
Up to 200,000 UTF-16 code units. Input and results stay in this tab.
IPv4/CIDR → netmask, network, host range; /31 point-to-point, /32 single host
IPv4 subnet calculator — What this tool does
IPv4 subnet calculator with local processing, input validation and downloadable results.
- Input and output
- IPv4/CIDR → netmask, network, host range; /31 point-to-point, /32 single host → TXT / JSON
How to use it
- Paste your input or use the example. Choose the input format before running.
- Adjust the available settings to suit the result you need. Your choices apply when you run the tool.
- Run the tool, review the result and any warnings, then download or copy the output. Larger files may take longer on your device.
Limits and output quality
Up to 200,000 UTF-16 code units. Input and results stay in this tab.
Runs locally. Use the example to check the input format; copy or download the result. Inputs are not saved across page reloads.
Frequently asked questions
What result will I get?
TXT / JSON. IPv4 subnet calculator with local processing, input validation and downloadable results.
Are my files uploaded to a server?
Files and text are processed in this browser tab, without server uploads or analytics. Language and theme preferences are saved on this device. Closing the tab releases the working files. On the first visit, the site uses the hosting provider’s approximate IP country when available, then your browser language. A language cookie remembers your choice for one year. You can change it at any time.
Will this change my original file?
No. The tool creates a separate result for you to review and download. Keep the original until you have checked the exported content.
Enter input to begin.
Enter input to begin.