The editor is free. Forever.
Plug in your own AI key and pay nothing. Or use ours: buy credits, spend them per request, top up when you want. No subscription, no seats, nothing expires.
Mathend
Free
$0forever
- Unlimited derivations and notes
- PDF and DOCX import and export
- Notes stay on your machine — no account needed
- Bring your own key: Claude, GPT, Gemini, Copilot, and more
- All future updates
Agent credits
Prepaid
No API key to manage. Every request is billed at cost plus a small margin, deducted from your balance.
$5
Try the hosted agent.
$10
A month of steady use.
$25
Heavy agent days.
Credits never expire. Unused balance stays on your account.
What credits buy
Fourteen models in three tiers. You are charged per token, so a short edit costs a fraction of a cent and only long sessions add up.
| Model | Input / 1M | Output / 1M |
|---|---|---|
| EconomyEdits, formatting, bulk rewrites — most turns cost a fraction of a cent. | ||
Hy3 The cheapest thing that still calls tools reliably. | $0.343 | $1.37 |
DeepSeek V4 Flash Very cheap per token and quick to answer. Good default for drafts. | $0.364 | $0.728 |
MiMo-V2.5 Cheap, long context, steady on mechanical edits. | $0.364 | $0.728 |
MiniMax M3 Fast and cheap. Good for edits, formatting, and bulk rewrites. | $0.780 | $3.12 |
Qwen3.7 Plus Balanced budget pick with a full million tokens of context. | $0.832 | $3.33 |
DeepSeek V4 Pro Stronger reasoning than Flash, still inside the economy band. | $1.13 | $2.26 |
MiMo-V2.5-Pro The larger MiMo. Cheap output for how much it gets right. | $1.13 | $2.26 |
| StandardMulti-step document work that has to come out right the first time. | ||
GLM-5.2 Reliable tool-caller. A good step up when economy models stall. | $1.34 | $4.21 |
Kimi K2.7 Code Tuned for code and structured output. 262k context. | $1.50 | $7.00 |
Qwen3.7 Max The big Qwen. Handles long documents without losing the thread. | $2.95 | $8.85 |
Grok 4.5 Fast for its size, and cheap on output. 500k context. | $4.00 | $12.00 |
Claude Sonnet 5 The everyday default. Strong at multi-step document work. | $4.00 | $20.00 |
| PremiumHard derivations and long proofs, where a wrong answer costs more than the tokens. | ||
Kimi K3 Frontier-class reasoning at a lower rate than Opus. | $4.80 | $24.00 |
Claude Opus 5 Hardest derivations and long proofs. Slower, and worth it. | $8.00 | $40.00 |
Rates can change when upstream prices do. The model menu in the app always shows the current one.