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Text Encryption Tool - 6 Text Transformation Options

Transform text using Base64, ROT13, Caesar cipher, XOR, and AES-256-GCM. All processing happens locally in your browser — this tool code does not upload or save your text or passphrase.

Text Encryption

Theme

Your text

Operation

Encrypt Decrypt

Base64 encodes text. ROT13, shifts and XOR are for obfuscation.

Method and key

Method

Result wrapper

For decoding or decryption, select the same wrapper used to create the result.

Input: 0 / 10,000 UTF-16 units

Built and maintained by Bhavin Sheth • Last updated September 10, 2026 •

Encoding and Encryption Options Explained

Compare encoding, obfuscation and authenticated encryption before choosing an option. Password quality and the browser environment affect protection.

01Encoding

Base64

Converts text into an ASCII-safe representation. Anyone can decode it — it hides nothing.

Used for: email attachments, data URLs, API payloads where binary-safe transport is needed.

02Encoding

ROT13

Rotates each letter by 13 positions. Reversible without a key — applying it twice returns the original.

Used for: hiding spoilers on forums, light casual obfuscation.

03Low

Caesar Cipher

Shifts letters by a fixed amount (default 3). Trivial to break by brute force — only 26 possible keys.

Used for: education, puzzles, children's secret messages.

04Low

Custom Shift

Same algorithm as Caesar with shifts between −25 and +25. Shifts wrap around modulo 26, so only 26 distinct letter substitutions exist.

Used for: custom puzzles, teaching cryptography basics.

05Obfuscation

XOR

Lightweight byte-level obfuscation using a repeating key. It should not be used as a replacement for authenticated encryption.

Used for: lightweight obfuscation when both sides share a simple key.

06Strong

AES-256-GCM

Industry-standard authenticated encryption via the browser's Web Crypto API. Uses PBKDF2 with 100,000 iterations, random salt, and random IV.

Used for: sensitive messages, private notes, short secrets, and data that needs authenticated encryption.

User Cases — Where & How Each Method Is Used

Real-world scenarios for each encryption option, with the specific workflow users follow in each case.

METHOD: Base64 — Where used: Email, APIs, data URLs

Sending binary-safe data over text channels

A developer has a JSON payload containing special characters that might get mangled in an email body or a legacy API. They encode it to Base64 first so the receiver can decode it safely on the other side.

How Paste JSON → select Base64 → Encrypt → copy the result into the email body → recipient selects Base64 → Decrypt.

METHOD: ROT13 — Where used: Forums, Discord, spoiler culture

Hiding plot spoilers from casual readers

A forum moderator wants to discuss a movie's ending without ruining it for people scrolling by. They ROT13 the spoiler so only readers who choose to decode it will see the content.

How Write the spoiler → select ROT13 → Encrypt → post the result with a note: "ROT13 to reveal." No key needed — same operation decrypts.

METHOD: Caesar / Custom Shift — Where used: Classrooms, puzzle books

Teaching cryptography or designing scavenger hunts

A teacher prepares a lesson on classical cryptography. Students receive ciphertext and must figure out the shift value by hand, learning how frequency analysis and brute force work on weak ciphers.

How Type the lesson plaintext → select Caesar Cipher (or Custom Shift) → use fixed shift 3 or set a Custom Shift → Encrypt → hand out to students with no key provided.

METHOD: XOR — Where used: Two people sharing a simple secret

Obfuscating a shared note between friends

Two friends want to pass a note through a shared Google Doc without the doc's contents being readable to anyone else with access. They agree on a passphrase beforehand and XOR the note with it.

How Agree on a key like "blue-sky-2026" → write the note → select XOR → paste the key → Encrypt → paste the result into the shared doc → friend pastes it back, selects XOR with the same key → Decrypt.

METHOD: AES-256-GCM — Where used: Wi-Fi passwords, private notes

Sharing a Wi-Fi password securely

A homeowner wants to send their Wi-Fi password to a guest via a messaging app they don't fully trust. They encrypt the password with AES-256-GCM using a strong passphrase, share the ciphertext through the app, and share the passphrase over a phone call.

How Type the Wi-Fi password → select AES-256-GCM → enter a long, unique passphrase → Encrypt → send the ciphertext via chat → share the key by phone → recipient decrypts with the same key.

METHOD: AES-256-GCM — Where used: Private journaling, cloud notes

Encrypting diary entries before saving to cloud

A user keeps a private journal in a notes app synced across devices. They encrypt each entry with a personal master key before pasting it in, which can protect the stored contents if the account is accessed, provided the passphrase and encryption environment remain uncompromised.

How Write the journal entry → select AES-256-GCM → enter the master key → Encrypt → paste the ciphertext into the notes app. To read later, paste it back, select Decrypt, enter the same key.

METHOD: AES-256-GCM — Where used: Small business communications

Protecting invoice numbers or client data in email

A freelancer emails a client a list containing account numbers and pricing. They encrypt the list with AES and a shared passphrase so intercepted emails remain unreadable.

How Paste the sensitive list → select AES-256-GCM → use the shared passphrase agreed on during onboarding → Encrypt → paste the ciphertext into the email body → recipient decrypts with the same passphrase.

METHOD: ROT13 + Caesar — Where used: Puzzle design, escape rooms

Layering ciphers in escape-room clues

A game designer wants a clue that requires two decoding steps. They ROT13 first, then Caesar shift the result. Players must reverse both steps in the correct order.

How Write the clue → ROT13 → copy the result → paste it back → Caesar shift by 7 → give the final ciphertext to players with no hints. Players must Caesar-unshift by 7, then ROT13 again.

Common Uses

Quick reference for which method fits which job.

Use case	Best method	Why
Sensitive text & secrets	AES-256-GCM	Strong, authenticated encryption; key shared through a separate channel.
API / email payloads	Base64	Preserves special characters during transport over text-only channels.
Spoiler hiding	ROT13	Keyless, reversible by anyone who chooses to decode.
Classroom cryptography	Caesar / Custom Shift	Simple enough to break by hand, ideal for learning.

Capabilities & Limitations

What this tool handles natively, and what it deliberately leaves to other software.

What it does

Offer six transformation options, including encoding, obfuscation and AES encryption.
Use real AES-256-GCM via the browser's Web Crypto API with PBKDF2 key derivation.
Process text locally without text or passphrase uploads in this tool code.
Never display the secret key in the result metadata.
Support the default result plus optional Hex and Base64 wrappers.

What it does not

Provide passphrase recovery or persistent text/key storage.
Encrypt files or images (text input only).
Provide strong encryption with ROT13, Caesar, or Base64 — these are encoding/obfuscation methods, not modern encryption.
Replace dedicated password managers or encrypted email services for ongoing communication.

Troubleshooting

Common errors and what they actually mean.

Decryption returns gibberish or "Decryption failed"

With AES-256-GCM this almost always means the key doesn't match what was used to encrypt. Even one wrong character will fail the authentication check. With XOR, a wrong key produces nonsense but no error — verify the key matches exactly.

"Output format does not match"

Select the same result wrapper used when creating the ciphertext. AES and XOR already produce Base64 in Default mode, so the appearance of Base64 text does not tell you whether an extra Base64 wrapper was applied.

AES encryption feels slow on long text

AES-256-GCM uses PBKDF2 with 100,000 iterations to derive the key — this adds computational cost to password guessing, but a weak or reused passphrase remains vulnerable. Use a long, unique passphrase. It's expected to take a short moment, especially near the 10,000-character limit.

Character limit reached

Encoding/encryption accepts 10,000 UTF-16 units; decoding/decryption accepts 200,000. An emoji can use more than one unit. Larger documents need dedicated file encryption software.

Frequently Asked Questions

Everything you need to know about encryption, privacy, and the methods available.

Is the encryption secure?

This tool processes text in your browser without uploading it through its code. AES-256-GCM uses the Web Crypto API with PBKDF2 key derivation for strong encryption, while methods like Base64, ROT13, and Caesar cipher are simple encodings intended for casual, non-sensitive purposes.

Do I need to create an account?

No account is required. The tool is free to use and processes text in your browser.

Which encryption methods can I use?

You can choose from Base64, ROT13, Caesar cipher, custom shift, XOR encoding, and AES-256-GCM for transforming your text.

Does this tool store my data?

No, all processing happens entirely in your browser. This tool code does not upload or save your text or passphrase. There is no passphrase recovery feature.

Is there a limit to how much text I can process?

Encoding or encryption accepts up to 10,000 UTF-16 code units. Decoding or decryption accepts up to 200,000 units to accommodate expanded results. For larger files, use dedicated file encryption software.