Local browser editing

Local Image Editor

Prepare photographs, figures, screenshots, scanned pages, signatures, stamps and other visual material directly in your browser. Image pixels remain on your device while you edit, copy, print or export them.

Open Local Image Editor View All Tools

Local processing Images, SVG files and imported PDF pages are processed on the device.

Multiple canvases Open several files, but edit and save each selected canvas separately.

Originals stay unchanged Saving downloads a new output file and does not overwrite the source.

On this page

Quick start Open files Canvases & navigation Selection & clipboard Crop tools Editing tools Background & drawing Save, PDF & print Keyboard shortcuts Troubleshooting Privacy & limits

Quick start

For most everyday jobs, the complete workflow is only five steps.

1 Open Select one or more image, SVG or PDF files, or drag them onto the workspace.

2 Choose a canvas Open Canvases and select the item you want to edit.

3 Open Tools Select + Tools, then open only the editing section you need.

4 Review Use Fit, zoom and Pan to check the complete result.

5 Save Select Save, choose a format and download the active canvas.

Safe editing: each change is made to the working canvas. Use Undo or Redo whenever needed. Your original file is not modified.

Open images, SVG files or PDF pages

Select Open or drag files onto the editor. You can choose several compatible files at the same time.

Source	What happens when opened	Important note
PNG, JPEG, WebP, GIF or BMP	Each file opens as a separate editable canvas.	An animated GIF is opened as a still image.
SVG	The SVG is rasterised locally at its intrinsic or viewBox dimensions.	Transparency remains, but individual vector objects are not separately editable.
PDF	A page selector appears. Every selected page becomes a separate image canvas.	Text, form fields and vectors become pixels. Use the Local PDF Editor when PDF structure must remain intact.

Importing PDF pages

Open the PDF and wait for its page thumbnails to appear.
Select the required pages, or choose Select available.
Choose Standard (108 dpi), High (144 dpi) or Very high (216 dpi). High is the normal default.
Select Import selected pages.
Open Canvases to move between imported pages.

PDF quality: choose Very high only when fine text or detail needs more pixels. It uses more memory and may take longer on a phone. Import is limited to documents of up to 300 pages.

Canvases and navigation

Work with several canvases

Use + Add to open more files.
Use + Canvases to expand the one-line canvas strip.
On a narrow phone, open More and choose Show canvases.
Select a thumbnail to change the active canvas. Each canvas keeps its own edits and undo history.
Saving or printing affects only the active canvas. Open canvases are never automatically combined.

Create a new blank canvas

Select New.
Choose a common size or enter exact width and height values.
Choose Transparent, White or Custom colour.
Select Create canvas.

Zoom, pan and mobile gestures

Select Fit to fit and centre the active image in the current screen orientation.
Use − and +, pinch with two fingers, or use Ctrl/Cmd with the mouse wheel.
Select ✋ Pan, then drag with one finger, a mouse or a pen.
When zoomed in, scroll horizontally and vertically to reach every image edge.
Rotating a phone between portrait and landscape recalculates Fit for the new viewport.

More working space: collapse Canvases and Tools when they are not needed. The tools can dock on either side of a desktop screen or above/below the editor on mobile.

Selection, cut, copy and paste

Copy or move part of an image

Open Tools → Select & clipboard.
Choose Rectangle or Freehand.
Drag over the required area.
Choose Copy, Cut or Delete selected area.
Choose Finish selection / Pan when finished.

Paste an image

Use Paste, Ctrl + V, or Cmd + V. The pasted content remains movable above the canvas until you choose Apply. Choose Cancel to discard it. Both actions return the editor to Pan mode.

Copy the complete canvas to another application

Open More and choose Copy active image. You can then paste the PNG image into compatible applications such as Word, PowerPoint or email.

On supported browsers, right-click the canvas to use Copy whole image, Copy rectangle, Copy freehand, Paste image or Finish selection / Pan. A long press may open the same editor menu when the mobile browser permits it.

Clipboard permission: copying an image outside the editor normally requires the HTTPS version of the site, browser permission and Clipboard API image support. Current desktop Chrome or Edge usually provides the best support. If copying is blocked, save the canvas as PNG and insert that file instead.

Crop tools

Rectangle crop

Choose Free, Square, 4:3, 3:2 or 16:9. Draw the crop draft, then drag a corner to resize it or drag inside the box to reposition it before applying.

Freehand crop

Draw around the area to keep. The blue line, white contrast halo and start marker remain visible. After drawing, drag near the outline to reshape it.

Edge trim

Draw one open line from one image edge to another. The editor completes the boundary and shades the smaller side red. Use Flip removed side if required.

Apply or cancel

Review and adjust the draft first. Select Apply crop only when ready, or choose Cancel to leave the current canvas unchanged.

Transparent result: a freehand crop removes everything outside the selected shape by making it transparent. Save as PNG or WebP to keep this transparency. JPEG fills transparent pixels with the selected JPEG background colour.

Text, shapes, size and colour

Add text

Enter one or more lines, choose the font, exact pixel size, colour and left/centre/right alignment, then select Place text and tap the image.

Shapes and arrows

Draw arrows, lines, rectangles, circles or ellipses. Choose line width, outline colour and an optional fill. A live preview appears while dragging.

Resize

Choose a common size or enter exact dimensions. Keep aspect ratio enabled to prevent distortion. Large reductions use progressive high-quality resampling.

Rotate and flip

Rotate by 90 degrees to the left or right, or flip the canvas horizontally or vertically. Every completed action can be undone.

Straighten

Adjust the angle from −45° to +45°. Crop edges avoids transparent corners; Expand canvas retains the complete rotated image.

Brightness and colour

Adjust brightness, contrast and saturation for the active canvas. Select Apply to commit the settings or Reset controls to restore neutral values.

Resizing cannot create missing detail: reducing a large image can remain clean, but enlarging a small or already compressed source cannot restore detail that is no longer present.

Remove backgrounds, paint and erase

Remove a plain background

Open Remove background.
Choose the background colour or select Pick from image and tap the background.
Start with Connected to image edges (safer).
Adjust Tolerance until the unwanted background is included without removing the subject.
Use Soft edge to smooth the transition, then select Remove background.

Choose Everywhere in image only when every matching pixel should be removed. This is useful for a simple signature on white paper, but it can also remove similar colours inside the subject.

Paint and erase

Select Paint, choose a colour and brush size, then draw with mouse, pen or touch.
Select Eraser to create transparent pixels instead of painting a solid colour.
Select Finish drawing to return to normal navigation.
Save as PNG or WebP if erased areas must remain transparent.

Best results: local colour-based background removal works best with a fairly plain, evenly lit background. It is not an online AI subject-segmentation service.

Save, export and print

Select Save to open Save / export. Only the active canvas is exported, even when several canvases are open.

Format	Best for	Transparency
PNG	Signatures, screenshots, text, logos and lossless output	Yes
JPEG	Photographs and smaller files with adjustable quality	No; transparent pixels receive the selected background colour
WebP	Compact modern images with adjustable quality	Yes, when supported by the browser
PDF	A one-page PDF containing the active canvas	The image is placed onto the chosen PDF page

Save as PDF

Choose PDF, then select Match the image, A4 or Letter. A4 and Letter automatically use portrait or landscape orientation so the image fits without distortion.

Target an output file size

For image formats, you may enter an optional minimum or maximum size in KB. Leave Reduce export dimensions enabled if the editor may reduce dimensions to meet the maximum. File-size limits are targets because browser encoders cannot guarantee an exact byte count; the result message reports the actual output size.

Print

Open More and choose Print active canvas, or use the Print button inside Save / export. The active canvas is fitted to the selected paper.

Free output footer: free saved, copied and printed outputs include a very small “Edited with BlitzTrials.com” footer at the absolute bottom. A signed-in account must be both verified and Premium to produce footer-free output. Account role by itself does not remove the footer.

On desktop, account information appears in the editor header. On mobile, open More. Signing in opens the main BlitzTrials sign-in page in another tab so the current canvas is not closed.

Keyboard shortcuts

Shortcut	Action
`Ctrl/Cmd` + `Z`	Undo
`Ctrl/Cmd` + `Y`	Redo
`Ctrl/Cmd` + `X`	Cut the current selection
`Ctrl/Cmd` + `C`	Copy the selection, or copy the complete canvas when nothing is selected
`Ctrl/Cmd` + `V`	Paste image content
`Ctrl/Cmd` + `N`	Create a new blank canvas
`Ctrl/Cmd` + `P`	Print the active canvas
`Ctrl/Cmd` + `S`	Open Save / export
`Ctrl/Cmd` + mouse wheel	Zoom the active canvas

Troubleshooting

The Tools button does not open

Close all open Image Editor tabs, reopen the editor once while online and refresh the page. This allows the latest offline cache to replace older mixed files.

The image is off-centre or part of it is outside the screen

Select Fit. For detailed work, select ✋ Pan, zoom in and drag or scroll to the required edge. After changing phone orientation, allow Fit to recalculate for the new screen size.

I pasted something and cannot leave selection mode

Choose Apply or Cancel in the action bar above the canvas. For a normal selection, choose Finish selection / Pan.

The freehand crop outline is difficult to see

The current editor displays a blue line, white halo and start marker. If these do not appear, close other editor tabs and reopen once online so the latest files are cached.

Transparent areas became white

Export as PNG or WebP. JPEG cannot store transparency and replaces transparent pixels with its selected background colour.

An imported PDF page looks blurry

Reopen the PDF and select High or Very high quality. Remember that the page is converted to pixels; use the Local PDF Editor when editable PDF structure or searchable text must remain intact.

Copy to Word or another application is blocked

Confirm that the hosted HTTPS page has clipboard permission and try current desktop Chrome or Edge. If the application or browser still blocks image clipboard writing, download a PNG and insert the downloaded file.

A large file will not open

Check the safety limits below. Very large images may also exceed the available memory of a mobile browser even when the file itself is within the limit.

Privacy, offline use and safety limits

What remains local

Opening, editing, copying, rasterising PDF/SVG content and encoding output files happen in the browser on the device. The editor does not upload the selected file or its pixels to BlitzTrials, Firebase or another image-processing service.

What the hosted site may access

Firebase is used only to check the signed-in BlitzTrials account and Premium entitlement. The shared site footer may load the configured translation and analytics services. These services are separate from the local image-processing workflow.

Offline use

Visit the hosted editor once while online so the browser can cache its application files. A downloaded standalone copy can continue editing locally without installation. A previously verified membership result may be cached for offline use for a limited period.

Safety limits

Maximum input file size: 150 MB.
Maximum image side: 16,384 pixels.
Maximum single canvas: 36 megapixels.
Maximum open canvases: 20.
Maximum combined open-canvas area: 60 megapixels.
Maximum PDF page selector: 300 pages.

Recommended habit: keep the original source file, export the edited result under a new name and review the final downloaded file before using it in research material.

Need more help?

Contact BlitzTrials support for help using the Image Editor or preparing visual material for the PDF Editor and research tools.

Contact Support