Base64 Encode Decode Offline
URL Hex JWT Hash Dev Tools
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Encode, decode, hash and inspect strings entirely on your iPhone. Base64, URL, hex, JWT, MD5 to SHA-512 — nothing you paste ever leaves the device.
Paste a Base64 string, tap once, read the answer — right on your iPhone, fully offline. No web converter, no upload, no wondering who just logged the token you pasted.
Base64 Encode Decode Offline is a developer scratchpad built for the real thing you paste: blobs copied out of logs and terminals. The decoder tolerates URL-safe alphabets, missing padding and line-wrapped copy-paste, auto-detects whether you meant encode or decode, and refuses garbage instead of returning silent nonsense. URL decoding is byte-accurate, so a leading BOM or odd byte is preserved instead of being quietly eaten. Everything renders in a proper monospaced font.
WHAT YOU GET
• A wrapped, unpadded, URL-safe Base64 blob from a log file still decodes cleanly — whitespace, CRLF and base64url handled for you
• Paste a JWT and read its pretty-printed header and payload immediately — the signature never touches a server
• One input, four digests: MD5, SHA-1, SHA-256 and SHA-512 update as you type, with one button to copy all four
• URL-encode a query value and the &, =, + and # characters that break query strings are actually escaped
• Turn any file into Base64 or a ready-to-embed data URI with the correct MIME type — and turn Base64 back into a file
• The String Inspector shows characters, UTF-8 / UTF-16 / UTF-32 byte counts, words and lines the moment text is entered
PERFECT FOR
• Backend and mobile developers debugging an API payload away from the laptop
• QA engineers inspecting auth tokens without pasting credentials into a website
• Sysadmins decoding config blobs and verifying checksums from a phone session
• Students seeing exactly how encodings and hash digests behave
WHY NOT JUST USE A WEB CONVERTER?
Because every online encode/decode tool receives your string on its server — and the strings developers convert are exactly the ones that should never leave the machine: session tokens, API keys, connection strings, JWTs. This app does all conversion and hashing on the device with Apple's CryptoKit. It works in airplane mode.
PRIVATE BY DEFAULT
No accounts, no tracking of your content, no network needed to convert. Your inputs and your conversion history are stored only on your iPhone.
FULL ACCESS
Pro unlocks unlimited saved conversions, file conversion beyond 5 MB in both directions, and Batch mode to convert many lines in one pass. Full access is available as a weekly subscription, a yearly subscription, or a one-time lifetime purchase.
Decode that string before the next station — download Base64 Encode Decode Offline.
Terms of Use: https://leanstudio.asia/terms-of-use
Privacy Policy: https://leanstudio.asia/privacy-policy
Support: support@leanstudio.asia
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First release of Base64Tool.
Subscriptions
In-App Purchases
The developer, LEAN ASIA CO., LTD, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- LEAN ASIA CO., LTD
- Size
- 3.5 MB
- Category
- Developer Tools
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Checksum Weekly $29.99
- Token Inspector Yearly $14.99
- Checksum Weekly $2.99
- Copyright
- © 2026 LEAN ASIA CO., LTD