runlocally

Small tools that run locally in your browser.

Convert, build, read and trim files — entirely on your device. Free, open source, and nothing is ever uploaded.

🔒 No upload. Your files never leave your device.

Images

HEIC to JPG

Convert iPhone HEIC photos to JPG or PNG.

WebP to JPG

Convert WebP images to JPG or PNG.

Rename Images in Sequence

Reorder photos, then download them renamed in sequence as a .zip.

ZIP & archives

Create ZIP

Bundle your files into a single .zip archive.

ZIP Viewer

See what's inside a .zip without extracting it.

Fix ZIP Filenames

Repair garbled (mojibake) filenames in a .zip.

Unzip

Extract a .zip and download its files.

Encrypt ZIP

Create a password-protected (AES-256) .zip.

Unlock ZIP

Remove the password from a .zip you can open.

Recover ZIP

Salvage files from a broken or corrupted .zip.

Remove from ZIP

Delete selected files from a .zip.

Merge ZIP

Combine multiple .zip files into one.

Split ZIP

Split a large .zip into smaller parts.

PDF

Split PDF

Extract page ranges into a new PDF.

Merge PDF

Combine several PDFs into one.

PDF to Image

Render PDF pages to PNG or JPG.

Extract PDF Text

Pull the text out of a PDF into a .txt file.

Audio & video

Remove Silence

Cut silent gaps out of an audio file.

Trim Audio

Cut an audio clip to a start and end point.

Data

CSV Viewer

Open and read CSV files right in your browser.

Hex Viewer

Inspect any file as a hex dump, right in your browser.

Documents

Eml Viewer

Open a saved .eml email and read it in your browser.

Winmail Viewer

Open a winmail.dat and download the real attachments.

Markdown Viewer

Open a local .md file and read it as sanitized, rendered HTML.

Edit Markdown Table

Edit a table in a grid — the Markdown syntax stays perfectly aligned.

Utilities

Draw Flowchart

Write flowchart syntax, see it rendered live. Export as SVG or PNG.

Edit Flowchart

Edit a Mermaid flowchart visually — structure only, code stays lossless.

Strip Tracking Params

Remove UTM/fbclid/gclid and other tracking params from a URL.

Format JSON

Pretty-print, validate, or minify JSON.

Compare Text

Diff two texts, line by line.

Edit ASCII Diagram

Edit a Unicode box-drawing diagram — CJK and emoji widths stay correctly aligned.

Identify File Type

Detect a file's real type from its binary signature, not its extension.

HAR Viewer

Inspect a .har network capture — requests, timing waterfall, headers — with warnings for exposed tokens.

Decode Certificate

Decode X.509 certificates and CSRs — no server ever sees the private material.

Format SQL

Pretty-print SQL queries across MySQL, PostgreSQL and more dialects.

Convert Color

Convert live between HEX, RGB and HSL with a preview swatch.

Convert Timestamp

Convert between Unix timestamps and human-readable dates.

Encode Base64

Encode or decode Base64, for text or binary files, byte-for-byte.

File Hash

Compute SHA-256, SHA-1 or MD5 for a file and compare against an expected value.

Password Generator

Generate cryptographically random passwords with guaranteed character-class coverage.

QR Code Generator

Turn text or a URL into a static QR code — no redirect or tracking layer.

Why "run locally"?

Privacy here is structural, not a promise — there is no server to upload to.

✓Nothing is uploaded. Files are read and processed in your browser.
✓Works offline. Each tool is a PWA you can install and use without a network.
✓Open source (MIT). The code is public — you can read exactly what runs.
✓No accounts, no tracking pixels. Just the tool and your files.