SMS Template Diff Tool
Compare two versions of a message template and catch changed variables, encoding changes, and segment or cost differences before you resend or resubmit for DLT approval.
Why a small edit can quietly double your SMS cost
SMS uses GSM-7 encoding by default, fitting up to 160 characters into a single segment. A single character outside that set, an emoji, a smart quote pasted from a document, or certain regional characters, forces the entire message into Unicode encoding, which drops the limit to 70 characters per segment. A template that fit in one segment can silently become two or three, and you're billed per segment.
What this tool checks
Paste the original approved wording as Template A and your edited version as Template B. The tool shows exactly which words changed, whether any {#...#} variable was added, removed, or renamed, whether the encoding flipped between GSM-7 and Unicode, and how the segment count compares.
Frequently Asked Questions
SMS uses GSM-7 encoding by default, fitting up to 160 characters in one segment. Adding a single character outside that set, such as a smart quote, emoji or certain regional characters, switches the whole message to Unicode encoding, which drops the limit to 70 characters per segment and can silently double the number of segments billed.
The tool extracts every {#...#} style placeholder from both templates and compares the two sets, flagging any tag that was added, removed, or renamed between versions. This helps confirm a template edit has not broken its match with an approved DLT template.
No. The comparison runs entirely in your browser using JavaScript. Nothing you paste into either template box is sent to or stored on our servers.
Not automatically. If a template is already DLT registered, any change to its fixed text or variable structure generally requires re-registration. Use this tool to see exactly what changed, then check the result with our DLT Template Format Validator before resubmitting.
Ready to register your template?
Talk to our team about DLT registration once your wording is finalized.
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