How local processing works

1. You choose a file

The browser gives the tool access to the file you select. The tool checks its type, size, and dimensions. Dragging a file into the selection zone follows the same local path.

2. Your browser does the image work

JPEG, PNG, WebP and supported still AVIF processing uses browser image decoding and canvas encoding. HEIC requires additional decoding code, downloaded from Reqly and run locally in a worker. A worker moves expensive work away from the page’s controls.

3. You inspect and download

The result is a local browser object with an image preview, measured byte size, and dimensions. Download saves that object to your device. No image upload is required.

PDF documents

Compress, Merge and Split PDF use a local writer worker and Mozilla PDF.js for previews and output checks. Compression rewrites document structure without downsampling images and retains the original when no smaller file is produced. Up to 500 pages and 64 MiB per PDF are accepted; merging allows 20 PDFs and 128 MiB total. Interactive, signed, encrypted and other unsupported documents are rejected. Metadata is retained during compression but is not copied to newly merged or split documents. This is not a metadata-removal service. Library, font and codec downloads are first-party static assets; documents do not leave the browser.

PDF.js license · PDF writer license

Video and encoded audio

Conversion, video editing and audio encoding use a first-party FFmpeg WebAssembly engine (about 31 MB, downloaded when processing starts). Processing happens in a worker on this device. Current limits are 256 MiB and 30 minutes per file, five files and 512 MiB per batch, with video up to 8192 pixels per edge and 35.4 megapixels. Each job stops after 15 minutes. Outputs are decoded again before download. The media engine can be reused for successive files: its virtual files are removed after each job, and the idle worker is terminated after 15 seconds, or when you reset or leave the page. Faster encoding is optional and may produce larger files; it does not silently change dimensions. These limits do not guarantee that every phone has enough memory. No server fallback is used. Video tools · Audio tools.

Browser-native audio tools

MP3 to WAV and Trim audio use native browser decoding, resampled to 48 kHz. A local worker writes 16-bit PCM WAV. Duration is checked before and after decoding; files are limited to 50 MiB and 10 minutes, with mono or stereo output. No audio is uploaded. Browser decoding support varies, and malformed metadata or low memory can still cause failure.

ZIP archives

Create ZIP, Extract ZIP, and Compress ZIP run in a local worker using fflate. The tools allow 128 MiB of selected data and expanded contents. Creation allows 200 files; reading a ZIP allows 1000 entries. Unsupported encryption, unsafe paths, inconsistent sizes, and failed checksums stop processing. The tools do not open or execute extracted contents. Recompression preserves file bytes but may replace ZIP timestamps, comments, and permissions. If it does not save space, the original is retained.

Batch and color tools

Batch tools process one image at a time and can assemble successful outputs into a ZIP locally. The pixel picker reads decoded pixels; the palette extractor groups colors from a reduced sample. Copy buttons write only the selected color code to your clipboard when pressed.

Screen color picking

Where the browser supports EyeDropper, you can pick a single displayed color after pressing Pick from screen. The browser returns its sRGB HEX value; Reqly calculates RGB and HSL locally. No screen image is received, recorded or uploaded by Reqly. Browsers may expose this API but still be unable to open it. Choose or paste a screenshot instead; pasted image files are read only in response to your paste action and follow the same local validation and pixel-reading path.

Background removal

The background remover downloads a BiRefNet Lite model only after you choose an image, then runs ONNX Runtime in a local browser worker. The first-use model and runtime transfer is about 113 MB before compression. If the primary mask is effectively empty, an alternate ISNet model is downloaded (another 88 MB) and tried once locally. An empty retry produces an error. The tool cannot automatically verify that every intended detail was kept; Restore and Erase edit the transparency mask locally. No image is uploaded when processing fails. Some devices do not have enough memory to run it.

Batch recovery is optional and off for each new batch. Enabling it stores photos, filenames, cutouts, results and options in IndexedDB on this browser. A saved batch can be reopened without uploading files or automatically restarting processing. Wait for the saved confirmation before closing. Start over leaves the saved copy; uncheck saving or choose Delete saved batch to remove it. Browser cleanup can remove saved data, and storage may be unavailable. This is not an offline-availability or secure-erasure promise.

Read the model MIT notice, ONNX Runtime license runtime third-party notices and alternate model source notes.

Why there are limits

A compressed file can expand into a much larger pixel buffer. A 16-megapixel image needs roughly 64 MB for just one RGBA buffer, and processing can use several. The tools enforce file and pixel limits, but a low-memory device may still fail.

When something is unsupported

The tool explains the failure. It does not send the file elsewhere, quietly substitute an output format, or claim that every browser supports every image.

Decoder credits and source

HEIC decoding uses libheif-js, libheif, and libde265. Read the decoder notices, source downloads, and replacement instructions.

ZIP assembly uses fflate. Its MIT license is included with the site.

Pro image preparation

Prepare images uses the existing local image worker for each source and variant, then checks the generated format, dimensions, byte limit, decodability and supported metadata. Size limits use at most four quality attempts from the original image. The target may remain unmet. Organized ZIP assembly runs in a separate local worker. Saved recipes use local storage only. Pro checks subscription access with the account server; those requests contain no files or recipe settings. No advertising scripts run in this workspace.

What local does not mean

The site still downloads pages and processing code. It is not a promise of offline availability or anonymous browsing. See Privacy for the complete scope.